2. Mineral Properties

The following table details Solitario’s capitalized mineral properties:

Solitario's mineral properties at March 31, 2026 and December 31, 2025 consist of use rights related to its exploration properties. The amounts capitalized as mineral properties include initial concession and lease or option acquisition costs. None of Solitario’s exploration properties have production (are operating) or have established proven or probable reserves. Solitario's mineral properties represent interests in properties that Solitario believes have exploration and development potential.

Exploration expense

The following items comprised exploration expense:

Asset Retirement Obligation and Reclamation Liabilities

Solitario recorded an asset retirement obligation of $125,000 upon the acquisition of its interest in the Lik Project for Solitario’s estimated reclamation cost of the existing disturbance at the Lik project. This disturbance consists of an exploration camp including certain drill sites and access roads at the camp. The estimate was based upon estimated cash costs for reclamation as determined by Solitario and its joint venture partner, Teck, and is supported by a permitting bond required by the State of Alaska, for which Solitario has retained a reclamation bond insurance policy in the event Solitario or Teck do not complete required reclamation.

Solitario has not applied a discount rate to the recorded asset retirement obligation as the estimated time frame for reclamation is not currently known, as completion of reclamation is not expected to occur until the end of the related project life, which would follow future development and operations, the start of which cannot be estimated or assured at this time. Additionally, no depreciation will be recorded on the related asset for the asset retirement obligation until the Lik project goes into operation, which cannot be assured.

As of March 31, 2026 and December 31, 2025, Solitario has no reclamation liability at its Florida Canyon Project as Nexa is responsible for the costs at the Florida Canyon project, including reclamation, if any. In addition, the activities to date at Solitario’s Cat Creek and Bright Angel projects of staking claims and mapping, soil and rock sampling, and assaying have not created any material environmental or other disturbances.

Solitario is also involved in certain matters concerning its 2024 and 2025 drilling program remediation at its Golden Crest project. Generally, the bulk of remediation at the Golden Crest project associated with its 2024 and 2025 drilling programs was carried out concurrently with drilling activities, with only ongoing contouring and reseeding of drill sites remaining as of March 31, 2026. At March 31, 2026 and December 31, 2025, Solitario has a reclamation liability of $20,000, included in asset retirement and reclamation liabilities related to the Golden Crest project.