Exhibit 99.1

S-K 1300 Technical Report Summary

Marigold Complex, Nevada, USA

SSR Mining Inc.

SLR Project No.: 138.020810.00001

Effective Date:

May 1, 2026

Signature Date:

October 9, 2026

Prepared by:

SLR International Corporation

Cautionary Note Regarding Forward-Looking Statements:

Certain statements contained in this report are "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and are intended to be covered by the safe harbor provided for under these sections. Forward looking statements can be identified with words such as “may,” “will,” “could,” “should,” “expect,” “plan,” “anticipate,” “believe,” “intend,” “estimate,” “projects,” “predict,” “potential,” “continue” and similar expressions, as well as statements written in the future tense. Forward-looking statements are based on information known at such time and/or with a good faith belief with respect to future events. Such statements are subject to risks and uncertainties that could cause actual performance or results to differ materially from those expressed in the forward-looking statements. Many of these risks and uncertainties cannot be controlled or predicted. Given these risks and uncertainties, readers are cautioned not to place undue reliance on forward-looking statements. Forward-looking statements include, among things: metal price assumptions, cash flow forecasts, projected capital and operating costs, metal recoveries, mine life and production rates, and other assumptions used in this report.

Such forward-looking information and statements are based on a number of material factors and assumptions, including, but not limited to: the inherent speculative nature of exploration results; the ability to explore; communications with local stakeholders; maintaining community and governmental relations; status of negotiations of joint ventures; weather conditions at our operations; commodity prices; the ultimate determination of and realization of Mineral Reserves; existence or realization of Mineral Resources; the development approach; availability and receipt of required approvals, titles, licenses and permits; sufficient working capital to develop and operate the mines and implement development plans; access to adequate services and supplies; foreign currency exchange rates; interest rates; access to capital markets and associated cost of funds; availability of a qualified work force; ability to negotiate, finalize, and execute relevant agreements; lack of social opposition to our mines or facilities; lack of legal challenges with respect to our properties; the timing and amount of future production; the ability to meet production, cost, and capital expenditure targets; timing and ability to produce studies and analyses; capital and operating expenditures; economic conditions; availability of sufficient financing; the ultimate ability to mine, process, and sell mineral products on economically favorable terms; and any and all other timing, exploration, development, operational, financial, budgetary, economic, legal, social, geopolitical, regulatory and political factors that may influence future events or conditions. While we consider these factors and assumptions to be reasonable based on information currently available to us, they may prove to be incorrect.

The above list is not exhaustive list of the factors that may affect any of the forward-looking statements and information included in this report, and such statements and information will not be updated to reflect events or circumstances arising after the date of such statements or to reflect the occurrence of anticipated or unanticipated events.

This technical report summary also contains financial measures which are not recognized under U.S. generally accepted accounting principles.

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Table of Contents

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Tables

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Figures

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SLR International Corporation (SLR) was retained by SSR Mining Incorporated (SSR) to prepare an independent Technical Report Summary (TRS) on the Marigold Complex (Marigold or the Property), located in Humboldt and Lander counties, Nevada, USA. The Marigold Complex includes the Marigold Mine (including Mackay, Valmy, and New Millenium) and the Buffalo Valley and Trenton Canyon deposits. SSR holds a 100% interest in the Property through its wholly owned subsidiary, Marigold Mining Company (MMC).

The purpose of this TRS is to disclose the results of the Mineral Resource and Mineral Reserve estimates for the Property with an effective date of May 1, 2026. This TRS conforms to United States Securities and Exchange Commission’s (SEC) Modernized Property Disclosure Requirements for Mining Registrants as described in Subpart 229.1300 of Regulation S-K, Disclosure by Registrants Engaged in Mining Operations (S-K 1300) and Item 601 (b)(96) Technical Report Summary. SLR visited the Property from June 10 to 12, 2026.

SSR has a diversified portfolio of operating, development and exploration assets across the Americas, including four operating mines in the USA, Canada, and Argentina. SSR is listed on the NASDAQ Global Select Market (NASDAQ:SSRM) and the Toronto Stock Exchange (TSX:SSRM).

SSR’s Marigold Complex is located approximately five kilometers (km) south–southwest of the town of Valmy, and approximately 24 km northwest of Battle Mountain. The open pit heap leach gold mine has been in production since 1989 and has produced over five million ounces of gold. The operation consists of several open pits, overburden storage areas (OBSA), leach pads, a carbon-in-column (CIC) adsorption facility, and a carbon processing and gold refining facility.

SLR offers the following conclusions by area.

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Marigold

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Buffalo Valley

Marigold

Buffalo Valley

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Integrated Operations

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Marigold

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Buffalo Valley

Marigold

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Buffalo Valley

Marigold

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Buffalo Valley

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SLR offers the following recommendations by area.

The SLR QP offers the following recommendations regarding advancement of the Property and improvement of the Resource model.

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SLR has no recommendations related to capital and operating costs.

An after-tax Cash Flow Projection has been generated from the Life of Mine production schedule and capital and operating cost estimates and is summarized in Table 1-1. A summary of the key criteria is provided below. The complete cash flow is presented in Section 27.0 Appendix.

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Marigold is subject to Nevada Net Proceeds of Minerals Tax, Nevada property and sales taxes, and U.S. federal income tax. The economic analysis calculates these taxes in accordance with legislation enacted as of January 1, 2022. Property and sales taxes are accounted for in the operating costs of the mine.

Nevada Gross Proceeds Tax

In 2021, the State of Nevada enacted Assembly Bill 495, effective July 1, 2021, which is an annual excise tax on gold and silver revenue. Under the bill, the tax rates vary based on the taxpayer’s Nevada gross revenue. A 0.75% rate is imposed on Nevada gross revenue of more than $20 million but not more than $150 million in a taxable year (defined as the calendar year). A rate of 1.10% applies to Nevada gross revenue exceeding $150 million in any tax year. The LOM average rate for Marigold Mining Complex during stacking is approximately 1.0% and averages $7.9 million per year over the fifteen years of mine operation.

Nevada Net Proceeds Tax

The State of Nevada imposes a 5% net proceeds tax on the value of all minerals extracted in the State. This tax is calculated and paid based on a prescribed net income formula applied only to income and expenses from mining, disallowing deductions for exploration and related-party financing costs. This tax is a deductible expense for U.S. federal income tax calculations and averages $17.8 million per year over the fifteen years of mine operation.

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US Federal Income Tax

Federal income tax is determined under regulations that came into effect on January 1, 2022. Under these regulations, which removed alternative minimum tax, the mine is subject to a federal income tax rate of 21%. SLR utilized Unit of Production depreciation, depletion allowances, and Net Operating Losses (NOL) as deductions. Total U.S. federal tax payable averages $23.1 million per year over the fifteen years of mine operation.

Royalties

Marigold is subject to a variety of NSR royalty payments, payable to various parties under the terms of the leases, as described in Section 3. The annual average NSR royalty payment is about 6.9% of gross revenue and averages $52.3 million per year over the fifteen years of mine operation. Net Smelter Return (NSR) royalty payments for the Buffalo Valley deposit are fixed at 3.5% of the value of production net of off-site refining costs.

Considering the Complex on a stand-alone basis, the undiscounted pre-tax cash flow totals $5,747 million over the mine life. The after-tax Net Present Value (NPV) at a 5% discount rate (midpoint with May 1, 2026, as time zero) is $3,334 million, as shown in Table 1-1.

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The World Gold Council Adjusted Operating Cost (AOC) is $1,809/oz Au. The mine life capital unit cost, including sustaining and closure/reclamation, is $253/oz, for an All in Sustaining Cost (AISC) of $2,062/oz Au. The average annual gold production during operation, excluding rinsing phase, is 196 koz per year over the fifteen year mine life and 78 koz per year during the five-year rinsing phase.

Project risks can be identified in both economic and non-economic terms. Key economic risks were examined by running cash flow sensitivities:

After-tax IRR sensitivity over the base case has been calculated for -20% to +20% variations for head grade, recovery, and gold price and operating and capital costs. The Project is most sensitive to changes in head grade, metallurgical recovery, and metal price (usually with same magnitude of impact) followed by operating cost and finally capital costs.

Economics for the operating Marigold gold mine complex are robust with respect to price, head grade, recovery, capital, and operating costs. The operations benefit from a long history of experience with mining heap leach gold recovery operations, and higher gold prices than originally planned.

Marigold is located in southeastern Humboldt County along the Interstate Highway 80 corridor in the northern foothills of the Battle Mountain Range, Nevada, U.S. Activities at the Property are centered at approximately 40°45′ N Latitude and 117°8′ W Longitude.

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The Property is situated approximately five kilometers south–southwest of the town of Valmy, Nevada, at Exit 216 off Interstate Highway 80. Other nearby municipalities include Winnemucca and Battle Mountain, Nevada, which lie approximately 58 km to the northwest and 24 km to the southeast of the Property, respectively.

The Marigold Complex includes two main land packages, the Marigold Land Package and the Sterling Land Package, collectively, the Property or project areas.

The Marigold Land Package encompasses approximately 10,440 hectares (ha), including the properties within the Marigold Mine Plan of Operations (PoO). The Sterling Land Package (9,169 ha) includes properties associated with the Trenton Canyon Mine and Buffalo Valley Mine.

Land and mineral ownership within the project areas are within the corridor initially governed by the Pacific Railroad Act of 1862, and, as such, these areas generally have a “checkerboard” ownership pattern. Mineral claims in Nevada are managed federally by the BLM. SSR holds a 100% interest in the Property through its wholly-owned subsidiary, MMC. Surface and mineral rights at the Property comprise the following: real property owned by MMC; unpatented mining claims owned by MMC; and leasehold rights held by MMC with respect to unpatented mining claims, mill site claims, and certain surface lands.

Some of the leases require MMC to make certain net smelter return (NSR) royalty payments to the lessors and comply with other obligations, including completing certain work commitments or paying taxes levied on the underlying properties. The NSR royalty payments are based on the specific gold-extraction areas and are payable when the corresponding gold ounces are extracted, produced, and sold. The NSR royalty payments vary between 0% and 10.0% of the value of gold production, net of off-site refining costs, which equates to an annual average ranging from 3.3% to 10.0% and a weighted average of 6.9% over the life-of-mine (LOM).

The first recorded gold production from the Property near Valmy, Nevada, occurred in 1938 when the Marigold Mining Company, owned by Frank Horton, operated an underground mine which came to be known as Marigold. The Horton family processed approximately 9,000 t of ore averaging about 6.85 g/t Au before World War II halted production. In 1943, Mr. Horton’s estate sold its interest in the Property and claims. Several unsuccessful attempts were made to open and operate the mine before exploration activities began again in 1968.

From 1968 through 1985, several companies conducted exploration programs in the Marigold area and completed a total of 126 exploratory drill holes. Records document the activities of Homestake (1968), St. Joe (1979), Decker Exploration (1979), Placer Amex (1979–1980), True North, Marigold Development Company (MDC) (1981–1983), Welcome North (1984), and Nevada North Resources (USA) Inc. (1985–1986). Other groups that conducted work in the area include Newmont, Kerr-McGee, SFP Minerals Corporation, Cordex/Rayrock Mines, and Vek/Andrus Associates (partnership between Vic Kral, Ralph Roberts, Bob Reeve, and Bill Andrus composed of Vek Associates and Andrus Resources Corporation).

The operating partner Cordex, an exploration syndicate composed of Dome Exploration (U.S.) Ltd., Lacana Gold Inc. (Lacana) and Rayrock Mines, leased the Vek/Andrus Associates claim block in September 1985 and began a drilling program in November 1985. Drill holes NM-3 and NM-4 intersected 21.3 m of 2.40 g/t Au and 25.9 m of 7.54 g/t Au, respectively. These were the discovery holes for the 8 South (8S) orebody.

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Following further drilling in the 8S deposit in the spring of 1986, a joint venture was formed between SFP Minerals and the Cordex group, which consolidated some of the land holdings over the Marigold area.

In late-1986, the Cordex group leased other claims, including the historical Marigold mine, Mackay (Top Zone, East Hill, and Red Rock) area from various claim holders.

In March 1988, Rayrock Mines (operating company for Cordex) made a production decision on the 8S deposit, and, by September 1988, it began stripping on the 8S pit (McGibbon, 2004).

In August 1989, the first gold doré bar was poured at the Marigold mill.

In March 1992, Rayrock Mines purchased a two-thirds ownership interest in the Property, and Homestake Mining Company (Homestake), which had taken Lacana’s interest through previous corporate mergers, held the remaining one third ownership interest in the Property.

In 1994, mining of the 8S deposit was completed, and the Marigold mill was no longer used to process ore. At this point, Marigold became a ROM heap leach operation.

In March 1999, Glamis Gold Ltd. (Glamis Gold) purchased all the assets of Rayrock Mines, resulting in Glamis Gold holding a two thirds ownership interest in Marigold, and Homestake continuing to hold a one third ownership interest. By January 2001, a total of one million ounces of gold had been recovered from the Property.

In 2006, Glamis Gold merged with Goldcorp Inc. (Goldcorp), resulting in a Goldcorp subsidiary holding a two-thirds ownership interest in Marigold and being the operator. Homestake, which had been acquired by Barrick Gold Corporation (Barrick) in 2001, continued to hold the remaining one-third ownership interest. In 2007, discovery holes were drilled in the Red Dot deposit.

By mid-2009, two million ounces of gold had been recovered from Marigold.

On April 4, 2014, SSR (formerly Silver Standard Resources Inc.) completed the acquisition of Marigold from subsidiaries of Goldcorp and Barrick.

In August 2015, Marigold mine acquired 2,844 ha of adjacent land from Newmont. This land included previously mined areas known as the Mud pit, NW pit, and the Valmy pits. Exploration drilling in the area had been completed by a combination of companies including Hecla Mining Company (Hecla), SFP Minerals, and Newmont.

In June 2019, SSR acquired the Trenton Canyon and Buffalo Valley properties from Newmont Goldcorp Corporation (Newmont). The Trenton Canyon target is located approximately four kilometers south of New Millenium and the Buffalo Valley target is located approximately 10 km southwest of New Millenium. Both properties are included in an 8,900 ha parcel that is contiguous to the south boundary of the Marigold property.

Marigold is located in the Battle Mountain district of north-central Nevada within the Basin and Range physiographic province bounded by Sierra Nevada to the west and the Colorado Plateau to the east. Paleozoic basement rocks of north-central to north-eastern Nevada generally comprise four distinct tectonostratigraphic assemblages: the eastern carbonate assemblage; the slope or transitional assemblage; the western siliceous and volcanic assemblage; and the overlap assemblage (Roberts, 1964). These rocks record a complex history of compressional and extensional tectonics and magmatism affecting the western margin of North America from the early Paleozoic through present. The Battle Mountain district hosts numerous mineral occurrences, including porphyry copper–gold, porphyry copper–molybdenum, skarn, placer gold, distal disseminated silver-gold, and Carlin-type gold systems.

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The gold deposits at Marigold are best characterized as Carlin-type deposits and cumulatively define a north-trending alignment of gold mineralized rock more than eight kilometers long. Gold mineralizing fluids were primarily controlled by fault structure and lithology, with tertiary influence by fold geometry. Within the Valmy Formation, higher gold grades are observed in the hinge zones of open folds that trend west-northwest and plunge gently. When viewed down plunge, the undulation of these folds is mimicked by gold mineralized horizons. The deposition of gold was restricted to fault zones and quartzite dominant horizons within the Valmy Formation and high permeability units within the Antler sequence.

The Buffalo Valley gold deposit is a distal disseminated silver-gold deposit and formed along a southeast trending zone of felsic porphyry dikes and faults. Gold occurs in arsenian iron sulfide overgrowths on pyrite in sheeted quartz+sericite+pyrite (QSP) veinlets within the central granodiorite and dacite porphyry dikes, subparallel to dike margins in the country rock, and within faults (e.g., the Front fault). Outboard of the intrusions, gold mineralization is stratiform in receptive horizons of Havallah sequence metasedimentary rocks.

Gold mineralization at Trenton Canyon is best described as a Carlin-type deposit and primarily hosted in a network of transtensional faults locally intruded by Eocene dikes and sills. Hydrothermal and/or phreatomagmatic breccias within these structures typically contain increased concentrations of gold. Gold mineralization is well confined to structures, although a small (several meter) halo of lower grade, more disseminated mineralization may be present. Quartz veining, illite, iron oxides, and iron hydroxides (goethite) are the primary indicators of gold mineralization where oxidized.

Since acquiring the Property in April 2014, SSR has conducted several surface exploration programs including soil sampling, geophysics, and in-fill/delineation drilling.

Reverse Circulation (RC) and Core (Diamond Drilling-DD) drilling on the Property is the principal method of exploration and delineation of gold mineralization after initial targeting using soil sampling and geophysical surveys. Drilling can generally be conducted year-round on the Property.

As of the effective date of this TRS, SSR and its predecessor companies have completed over 2.6 million meters of drilling in approximately 13,000 drillholes across the Marigold, Buffalo Valley, and Trenton Canyon areas.

Since 2022, exploration at the Property has focused on the following:

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Since the last technical report (SLR 2024), 731 holes have been drilled (663 RC holes and 68 diamond core holes), totaling 157,220 m.

Mineral Resources have been classified in accordance with the definitions for Mineral Resources in S-K 1300. SLR has reviewed, audited, and accepted the Mineral Resource estimates prepared by SSR and Red Pennant Geoscience Consulting (Red Pennant) for Marigold and Buffalo Valley, respectively. The Mineral Resource estimates are based on block model values developed from assays on the mineralized properties. The Marigold Mine and Buffalo Valley Mineral Resources as of May 1, 2026, are summarized in Table 1-2.

The Mineral Resource estimates were completed using Seequent’s Leapfrog Geo (Leapfrog Geo) software for Marigold and Buffalo Valley.

Estimates were validated using standard industry techniques, including statistical comparisons with composite samples and parallel inverse distance squared (ID2) and nearest neighbor (NN) estimates, swath plots, and visual reviews in cross-section and plan. A visual review comparing blocks to drill holes was completed after the block modeling work was performed to ensure general lithologic and analytical conformance and was peer reviewed prior to finalization.

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Mineral Reserves in this TRS are derived from the current Mineral Resources. The Mineral Reserves are reported as contained gold and are based on open pit mining from Marigold and Buffalo Valley Mines. The Proven and Probable Mineral Reserves for Marigold are estimated as of May 1, 2026, and summarized in Table 1-3.

SLR is not aware of any risk factors associated with, or changes to, any aspects of the modifying factors such as mining, metallurgical, infrastructure, permitting, or other relevant factors that could materially affect the Mineral Reserve estimate.

Marigold Mine is mined using conventional surface mining methods. The Marigold Mine uses large 300 st mining trucks, and some areas of the pit require long hauls to the leach pads. The surface operations include:

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The Mineral Reserve is based on the ongoing annual average ore production from the Mackay (includes the Red Dot area), Valmy, DG80, North Mackay, and New Millenium areas, as well as Buffalo Valley – a satellite pit with a planned commencement in 2029 -delivering an average of approximately 200 koz recovered over the 15 years of active mining.

Mining and processing operations are scheduled 24 hours per day, and the mine production is scheduled to directly feed the leach pads.

The current LOM plan for the Marigold Mine and Buffalo Valley Mine provides 20 years of operational life, including 15 years of active mining followed by an additional five years of processing the heap leach pad inventory. The average stripping ratio from the pits, excluding the stockpile ore, is 5.3 waste units to 1 unit of ore (5.3:1 stripping ratio).

There are 33 mining pits/phases in the four mining areas of the Marigold Mine with varying dimensions, with a maximum depth of approximately 460 m attained in the Red Dot pit area. In addition, the Buffalo Valley area will comprise two additional phases for Buffalo Valley and Ore Hills.

Primary production for all mine pits includes drilling 22.2 cm diameter blast holes. A production blast hole of 16.7 m depth is drilled. Burden and spacing vary depending on the material being drilled. The holes are filled with explosives and blasted. A combination of hydraulic excavators and electric shovels load the broken material into 300 st-payload mining trucks for transport from the pit to the overburden storage areas (OBSAs) and leach pads.

The major pieces of pit equipment include electric shovels, hydraulic excavators, front end loaders, haul trucks, drills, bulldozers, and graders. Extensive maintenance facilities are available at the mine site to service mine equipment.

Marigold headcount is 540 persons, which includes personnel in mine operations, mine maintenance, geology, process and laboratory, and general and administration. For the 2027 to 2040 LOM period, the workforce is projected to increase to a total of 686 personnel, comprising 578 employees and 109 contractors.

Marigold

The Marigold processing facilities combine industry standard ROM cyanide heap leaching, recovery of gold from the leach solution using carbon adsorption, desorption, electrowinning, and refining circuits (ADR) to produce a final precious metal product.

The heap leach pad was originally constructed in 1990 and has since expanded as required, with ongoing expansion of solution processing facilities to match production rate and leach area. Approximately 427 hectares of heap leach pads are divided into 27 cells, along with six pregnant (gold-bearing) solution ponds and two barren solution ponds. There are 17 cells currently active.

ROM ore is delivered from the mine at a rate of approximately 20 Mt per year to the leach pad by mine haul trucks and stacked in 6 m to 12 m lifts.

Barren leach solution is pumped to the leach pad by two independent barren solution distribution systems. Combined barren solution flow capacity from the two pumping systems is 3,400 m³/h. In 2026, upgrades are underway to increase barren solution pumping capacity to 4,540 m³/h. Drip tubing is used to distribute the barren solution from the main barren solution pipelines to each cell. Solution is applied to the ore at a rate of 4.6 L/h/m² to 8.6 L/h/m² using drip emitters, impact sprinklers, wobblers, or drip emitters are used to irrigate the side slopes of the heap.

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Pregnant solution from the leach pad is collected in the pregnant solution ponds and pumped to the carbon-in-column (CIC) adsorption plant located on the north side of Barren Pond No. 1 to recover the gold by adsorption. The carbon adsorption circuit consists of seven parallel carbon column trains, each with five columns. Four new trains are being installed in 2026 to match the barren pumping upgrades currently underway.

Loaded carbon from carbon adsorption is transported by a dedicated truck to the nearby carbon processing facility where gold is eluted (re-dissolved) from the carbon in two 2.7 t capacity carbon elution vessels. Gold is eluted from the carbon using the Pressure Zadra process where a hot caustic solution at approximately 140°C is circulated under pressure through the elution column, from bottom to top. The resulting rich gold eluant flows through two parallel 2.8 m³ electrowinning cells to recover the gold. The barren eluant discharging the electrowinning cells is recirculated through heat exchangers to the bottom of the elution vessel to strip more gold. The process continues until the majority of the gold is recovered from the carbon.

The stripped carbon is acid washed with hydrochloric acid. The acidified carbon is then neutralized with water in the same column. The carbon is discharged from the column and transferred to the reactivation kiln. The carbon is reactivated as required by heating in a rotary kiln at 750°C. The reactivated carbon is quenched and screened before being returned to the carbon adsorption circuit to be reloaded with gold.

The plated material (sludge) resulting from electrowinning is collected in a filter press and then retorted for drying and mercury removal. After retorting, the sludge is mixed with flux and smelted in a propane fired furnace for final precious metal recovery.

Buffalo Valley

The design of the Buffalo Valley processing facilities follows the same philosophy as is utilized at Marigold. A multi-cell heap leach pad, designed to accommodate the expected mining rate up to 14 Mtpa, will be truck-stacked either with ROM or crushed ore in 7.5 m to 12.5 m lifts. Cyanide solution will be applied to the surface at a nominal rate of 8 L/h/m², which will percolate through the ore, dissolving precious metals, before being collected in a drain network at the plastic liner.

Pregnant solution will flow by gravity directly into a pregnant solution tank, then be pumped to three CIC carbon column trains for adsorption. It was determined that three 9,779 m³/h trains, with five 9,779 m³/h columns per train, provide the best balance of maintenance and production flexibility.

Loaded carbon from the carbon adsorption circuit will be transferred to a loaded carbon storage tank, which will then be pumped into a carbon transfer truck and transported to the Marigold elution facility for acid washing, elution, and reactivation.

Barren carbon will be loaded into the carbon transfer truck and returned to the Buffalo Valley process plant. Barren carbon will be pumped from the carbon transfer truck into a barren carbon storage tank before being returned to the adsorption circuit.

Barren process solution will be pumped to the irrigation system from a barren solution concrete vault using vertical turbine pumps.  After percolating through the ore, the gold-bearing pregnant leach solution will drain by gravity to a pregnant solution tank, where it will be collected and pumped to the carbon adsorption circuit for metal recovery.

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Marigold

Marigold is accessible via Interstate Highway 80 in northern Nevada and is approximately 5 km south-southwest of Valmy in Humboldt County. The site access road supports two lanes of traffic and consists of hard packed clay and gravel.

The infrastructure facilities at Marigold include ancillary buildings, offices and support buildings, access roads into the plant site, power distribution, source of fresh water and water distribution, fuel and reagents supply, storage and distribution, waste management and communications.

The power supply for Marigold is provided by NV Energy Inc. via a 120 kV transmission line to site. Site power draw is 5 MW. After exiting the main substation, power is distributed through a 25 kV distribution grid.

Water for Marigold is supplied from three existing groundwater wells located near the access road to the Property and the site’s network of pit dewatering wells. Marigold owns groundwater rights and collectively allows up to 3.134 million m³ of water consumption annually for site operations. Total water consumption by the site has averaged 1.52 million m³ per annum, over the past five years. The water is primarily consumed by retention in the heap leach pad, evaporation, processing operations and dust suppression.

The following buildings and facilities are in the main plant and offices area:

Additional buildings and facilities on site include:

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Buffalo Valley

The initial site layout for Buffalo Valley was developed from the Newmont Plan of Operations acquired as part of the purchase of the property. The need for a Marigold to Buffalo Valley connector road was confirmed and fully engineered by WSP during the Feasibility Study (SSR 2026b).

SSR conducted trade-off studies to evaluate site warehouse and haul truck maintenance shop locations. Given the short mine life of Buffalo Valley, SSR decided to use the Marigold truck shop rather than build a new truck shop at Buffalo Valley. No other maintenance facilities are planned at Buffalo Valley.

Buffalo Valley will need to construct approximately 14.5 km of 24.9 kV power line from the existing North Peak power line to service the Buffalo Valley site. Line power will be stepped down to 4,160 V, 480 V, and 110 V as required with power primarily distributed at 4,160 V or 480 V to motor control centers serving the respective process areas.

Currently, the North Peak substation is fed from the existing Marigold mine substation, supplied by NV Energy. Three site-area transformers will be required at different locations throughout Buffalo Valley. The anticipated transformer-connected loads are 6.53 MW, and the calculated demand loads are 4.61 MW (including the crushing circuit and pit dewatering pumps). The new overhead power line from North Peak to Buffalo Valley will be routed along the new Marigold/Buffalo Valley connector road. 

The Marigold Mine produces gold and silver contained in doré. Marigold is an active producer and has been for over three decades.

Gold is the principal commodity at the Marigold Mine and is freely traded at prices that are widely known, so that prospects for sale of any production are virtually assured. A gold price of $2,200/oz Au was used for estimation of Mineral Reserves and a long-term price of $3,948/oz Au was used for the economic analysis.

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Specific federal, state, and local (Humboldt County, Nevada) regulatory and permitting requirements apply to MMC, including the Plan of Operations (PoO) permitted via the United States (U.S.) Bureau of Land Management (BLM); the Water Pollution Control Permit (WPCP) issued by the Nevada Department of Environmental Protection (NDEP); the temporary discharge permit allowing for the discharge of dewatering water to rapid infiltration basins (RIBs) issued by NDEP; and the reclamation permit issued by the Nevada Bureau of Mining Regulation and Reclamation (BMRR).

MMC currently holds active, valid permits for all current facets of the mining operation. MMC is currently in compliance with all permits. At present, there are no known environmental issues that impact the ability to extract Mineral Resources at the Property. All activities associated with MMC require an approved reclamation plan that includes a Reclamation Cost Estimate (RCE) for all permitted facilities and activities. This was updated and approved by federal and state agencies in 2026. MMC is actively engaged with the local communities and stakeholders and there are no outstanding negotiations or social commitments for the operation of the mine.

SSR’s forecasted capital and operating cost estimates related to the development of Mineral Reserves are derived from annual budgets and historical actuals over the life of the current operation. According to the American Association of Cost Engineers (AACE) classifications, these estimates would be Class 1 with an accuracy range of -3% to -10% to +3% to +15%.

LOM project capital costs, which considers all costs incurred before May 1, 2026, as sunk, are summarized in Table 1-4.

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The LOM (from May 1, 2026) operating costs estimate is $16.78/t of stacked ore, as shown in Table 1-5.

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SLR International Corporation (SLR) was retained by SSR Mining Inc. (SSR) to prepare an independent Technical Report Summary (TRS) on the Marigold Complex (Marigold or the Property), located in Humboldt and Lander counties, Nevada, USA. The Marigold Complex includes the Marigold Mine (including Mackay, Valmy, and New Millenium) and the Buffalo Valley and Trenton Canyon deposits. SSR holds a 100% interest in the Property through its wholly owned subsidiary, Marigold Mining Company (MMC).

This TRS conforms to United States Securities and Exchange Commission’s (SEC) Modernized Property Disclosure Requirements for Mining Registrants as described in Subpart 229.1300 of Regulation S-K, Disclosure by Registrants Engaged in Mining Operations (S-K 1300) and Item 601 (b)(96) Technical Report Summary.

SSR has a diversified portfolio of operating, development and exploration assets across the Americas, including four operating mines in the USA, Canada, and Argentina. SSR is listed on the NASDAQ Global Select Market (NASDAQ:SSRM) and the Toronto Stock Exchange (TSX:SSRM).

SSR’s 100% owned Marigold Complex is an open pit heap leach gold mine operation, which has been in production since 1989 and has produced over five million ounces of gold. The operation consists of several open pits, overburden storage areas (OBSAs), leach pads, a carbon-in-column (CIC) adsorption facility, and a carbon processing and gold refining facility.

SLR qualified persons (QPs) visited the site on June 10 to 12, 2026. During the site visit, the SLR QPs received a project overview by site management with specific activities as follows:

The SLR geology QP toured operational areas and project offices, inspected various parts of the property and infrastructure, inspected the core handling facility, reviewed sampling procedures, and interviewed key personnel involved in the collection, interpretation, and processing of geological data and in the preparation of the Mineral Resource estimates.

The SLR mining QP toured operational areas and project offices, inspected various parts of the mining operations and infrastructure, and interviewed key personnel involved in the operations and in the technical services involved in the preparation of the Mineral Reserve estimates and Life of Mine (LOM) plan.

On behalf of the SLR metallurgy QP, a SLR Principal Metallurgist conducted a site visit of the operational areas and project offices. The site visit tour included the in-operation heap leach pad, the inactive heap leach cells, the barren and pregnant solution ponds, the carbon-in-columns (CIC) system, and the acid wash, elution, and regeneration plant. During the tour, the SLR Principal Metallurgist interviewed the operations superintendent, senior metallurgist, and environmental manager. Based on these conversations, SLR understands that SSR is expanding CIC capacity by adding four CIC trains and upgrading the barren solution booster pumping system, and that SSR is conducting some debottlenecking in the acid wash, elution, and regeneration circuit by installing a separate scrubber in the gold room. More copper has recently been present in the doré. The SLR Principal Metallurgist also met with the chief metallurgist to discuss future column test equipment, planned column testing, and aspects of the heap leach recovery model.

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During the preparation of this TRS, discussions were held with personnel from SSR:

This report is an update of a Technical Report Summary with a report date of February 12, 2024 (SLR 2024).

This TRS was prepared by SLR QPs. The TRS is based on information and data supplied to the QPs by SSR and other parties where necessary. The documentation reviewed and other sources of information are listed at the end of this TRS in Section 24.0 References.

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Units of measurement used in this TRS conform to the metric system or the US Common system. All currency in this TRS is US dollars (US$) unless otherwise noted.

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Marigold is located in southeastern Humboldt County along the Interstate Highway 80 corridor in the northern foothills of the Battle Mountain Range, Nevada, U.S. Activities at the Property are centered at approximately 40°45′ N Latitude and 117°8′ W Longitude.

The Property (Figure 3-1) is situated approximately five kilometers south–southwest of the town of Valmy, Nevada, at Exit 216 off Interstate Highway 80. Other nearby municipalities include Winnemucca and Battle Mountain, Nevada, which lie approximately 58 km to the northwest and 24 km to the southeast of the Property, respectively.

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SSR holds 100% interest in the Property through its wholly owned subsidiary, Marigold Mining Company (MMC). Surface and mineral rights at the Property comprise real property owned by MMC; unpatented mining claims owned by MMC; and leasehold rights held by MMC with respect to unpatented mining claims and mill site claims and surface lands.

The properties described herein are associated with one of two main land packages, the Marigold Land Package and the Sterling Land Package (both also referred to as project areas) totalling approximately 19,609 ha (Table 3-1, Figure 3-2). The Marigold Land Package (10,440 ha) includes the properties within the Marigold Mine PoO. The Sterling Land Package (9,169 ha) includes properties associated with the Trenton Canyon Mine or Buffalo Valley Mine.

Land and mineral ownership within the PoO are within the corridor initially governed by the Railroad Act, and, as such, these areas generally have a “checkerboard” ownership pattern. Mineral claims in Nevada are managed federally by the Bureau of Land Management (BLM).

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Surface lands at Marigold owned by MMC are listed in Table 3-2.

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MMC owns a total of 347 unpatented mining claims within the Marigold project area, as shown in Table 3-3, and 499 unpatented mining claims within the Sterling (Trenton Canyon and Buffalo Valley) project area, as shown in Table 3-4.

All claims, which are renewed annually in September of each year, are in good standing until September 1, 2027 (at which time they will be renewed for the following year as a matter of course). All unpatented mining claims are subject to an annual federal mining claim maintenance fee of $200 per claim plus approximately $12 per claim for county filing fees to the BLM.

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