美国黄金矿业公司美国存托凭证招股说明书（2026年6月26日版）

Up to $2,116,998.60 Common Stock This prospectus supplement amends and supplements the information in the prospectus, dated May 28, 2024 (the “ATM Prospectus”),to the accompanying base prospectus, dated May 28, 2024 (the “Base Prospectus” and, collectively with the ATM Prospectus, the“Prospectus”), filed as a part of our registration statement on Form S-3 (File No. 333-279435) (the “Registration Statement”), assupplemented by the prospectus supplement, dated September 30, 2025 and the prospectus supplement, dated December 12, 2025,relating to the offering, issuance and sale by us of our common stock, par value $0.001 per share (“Common Stock”), from time totime that may be issued and sold under the At The Market Offering Agreement (the “Sales Agreement”), dated May 15, 2024, withH.C. Wainwright & Co., LLC, as lead agent (the “Lead Agent”) and the co-agents party thereto (collectively with the Lead Agent, the“Sales Agents”). Through the date hereof, we have sold an aggregate of $10,723,983 of shares of our Common Stock through the SalesAgents under the Sales Agreement. This prospectus supplement should be read in conjunction with the Prospectus, and is qualified by The purpose of this prospectus supplement is to decrease the amount of shares we are offering pursuant to the Sales Agreement and theProspectus, such that we are now offering to sell shares of our Common Stock having a maximum aggregate offering price of up to As of the date of this prospectus supplement, the aggregate market value of our outstanding Common Stock held by non-affiliates, orthe public float, was $44,713,619.28, which was calculated based on 3,304,776 shares of our outstanding Common Stock held by non-affiliates at a price of $13.53 per share, the closing price of our Common Stock on the Nasdaq Capital Market on May 5, 2026. Duringthe 12 calendar months prior to, and including, the date of this prospectus supplement, we sold securities with an aggregate marketvalue of approximately $8,998,493.72 pursuant to General Instruction I.B.6 of Form S-3. After giving effect to the offering limit Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on page 3 of the ATM Prospectus andany similar section included in any accompanying prospectus supplement and in the documents incorporated by reference inthe ATM Prospectus for a discussion of the factors you should carefully consider before deciding to purchase these securities. Our Common Stock are listed on the Nasdaq Capital Market under the symbol “USGO”. On June 25, 2026, the last reported sale priceof our common stock as reported on the Nasdaq Capital Market was $8.06 per share. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of thesesecurities or passed upon the adequacy or accuracy of this prospectus supplement. Any representation to the contrary is acriminal offense. Lead Agent H.C. Wainwright & Co. Co-Agents Stifel Ventum Financial Corp. The date of this prospectus supplement is June 26, 2026.