Summary of Significant Accounting Policies and Business Operations (Policies) |
3 Months Ended |
|---|---|
Mar. 31, 2026 | |
| Organization, Consolidation and Presentation of Financial Statements [Abstract] | |
| Business Operations [Policy Text Block] |
Business Operations Thunder Mountain Gold, Inc. ("Thunder Mountain", "THMG", or "the Company") was originally incorporated under the laws of the State of Idaho on November 9, 1935, under the name of Montgomery Mines, Inc. In April 1978, the Montgomery Mines Corporation was obtained by a group of the Thunder Mountain property holders and changed its name to Thunder Mountain Gold, Inc., with the primary goal to further develop their holdings in the Thunder Mountain Mining District, located in Valley County, Idaho. Thunder Mountain Gold, Inc. takes its name from the Thunder Mountain Mining District, where its principal lode mining claims were located. For several years, the Company's activities were restricted to maintaining its property position and exploration activities. During 2005, the Company sold its holdings in the Thunder Mountain Mining District. During 2007, the Company acquired the South Mountain Mines property in southwest Idaho and initiated exploration activities on that property, which continue today. |
| Basis of Presentation and Going Concern [Policy Text Block] |
Basis of Presentation and Going Concern The accompanying consolidated financial statements have been prepared under the assumption that the Company will continue as a going concern. The Company has historically incurred losses, however, the Company has cash reserves sufficient to cover normal operating expenses for the following 12 months. If necessary, the Company continues to have the ability to raise additional capital in order to fund its future exploration and working capital requirements. |
| Principles of Consolidation [Policy Text Block] |
Principles of Consolidation The condensed consolidated financial statements include the accounts of the Company; its wholly owned subsidiaries, Thunder Mountain Resources, Inc. ("TMRI") and South Mountain Mines, Inc. ("SMMI"); and a company in which the Company owns 75% and has majority control, Owyhee Gold Trust, LLC ("OGT"). The Company's consolidated financial statements reflect the other investor's 25% noncontrolling, capped interest in OGT. Intercompany accounts are eliminated in consolidation. |
| Accounting Estimates [Policy Text Block] |
Accounting Estimates The preparation of the condensed consolidated financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosures of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. The more significant areas requiring the use of management estimates and assumptions include the carrying value of properties and mineral interests, environmental remediation liabilities, deferred tax assets, and stock-based compensation. Management's estimates and assumptions are based on historical experience and other assumptions believed to be reasonable under the circumstances. Actual results could differ from those estimates. |
| Recent Accounting Pronouncements [Policy Text Block] |
Recent Accounting Pronouncements Accounting Standards Updates In November 2024, the Financial Accounting Standards Board ("FASB") issued ASU 2024-03, Disaggregation of Income Statement Expenses (Subtopic 220-40). The standard requires public business entities to disclose additional information about certain expense categories included in income statement captions, including purchases of inventory, employee compensation, depreciation, depletion, and amortization. The amendments also require qualitative disclosures regarding other significant expense components included within the same income statement captions. The guidance is effective for annual reporting periods beginning after December 15, 2026, and interim periods beginning after December 15, 2027. The company is currently evaluating the impact of the standard on its consolidated financial statement disclosures. |
| Net Income (Loss) Per Share [Policy Text Block] |
Net Income (Loss) Per Share The Company is required to have dual presentation of basic earnings per share ("EPS") and diluted EPS. The Company calculates basic earnings (loss) per share by dividing net income or loss available to common stockholders by the weighted average number of common shares outstanding during the applicable reporting period. Diluted earnings per share reflect potentially dilutive common stock equivalents, including options and warrants that could share in our earnings through the conversion to common shares, except where their inclusion would be anti-dilutive. For the three months ended March 31, 2026 and 2025, outstanding warrants of 22,400,000 and 12,400,000, respectively, and outstanding stock options of 5,945,000 and 4,865,000, respectively, were excluded from the calculation of diluted earnings per share, as their effect would have been anti-dilutive due to the net loss for the periods. |