U.S. GoldMining Reports 85% Gold, 79% Copper, 55% Silver Recovery At Whistler Project; Validates Flotation-Leach Flowsheet Ahead Of PEA

U.S. GoldMining Inc. (NASDAQ:USGO) ("U.S. GoldMining" or the "Company") is pleased to announce updated results from the metallurgical test work program (the "Program") which commenced earlier this year (see news release dated April 24, 2025) for the Whistler Gold-Copper Project ("Whistler" or the "Project"), located 105 miles northwest of Anchorage, Alaska.

Highlights:

Recovery of up to 85.3% gold (Au), 79.1% copper (Cu) and 55.3% silver (Ag) from the combined sulphide flotation and leaching test work using a master composite derived from Whistler Deposit drill core that is representative of the average metal grade within the Project's mineral resource estimate ("MRE").

Sulphide flotation locked cycle tests ("LCT") produced a copper concentrate grading 23.7% Cu with a 0.6% mass pull at a P80 grind size of 120µm (rougher circuit) and a regrind of 16µm (cleaner circuit). The initial concentrate metal recoveries include 54.1% Au, 79.1% Cu and 55.3% Ag.

Leach testing of the rougher sulphide flotation circuit tails recovered an additional 31.2% Au, for the combined overall recovery of 85.3% Au.

A total of 28 flotation tests were completed together with four leach tests on a combination of master composites and variability samples that were conducted by Base Metallurgical Laboratories Ltd., of Kamloops, B.C., Canada.

The Program results provide key metallurgical recovery and process flowsheet inputs to the initial economic assessment (the "PEA").