Thunder Mountain Gold, Inc.

Thunder Mountain Gold Significantly Increases Land Position at The South Mountain Property

Boise, Idaho--(Newsfile Corp. - June 1, 2026) - Thunder Mountain Gold, Inc. (OTCQB: THMG) (TSXV: THM) ("Thunder Mountain Gold" or the "Company") is pleased to announce that it has secured a 20-year mineral lease ("Lease") with the Idaho Department of Lands ("IDL" or the "Lessor"), through its wholly owned subsidiary, South Mountain Mines Inc., covering approximately 3,675 acres of state-owned land adjacent to the Company's South Mountain Mines Property in Owyhee County, Idaho. The Lease expands the Company's district-wide land position at South Mountain and supports continued exploration, development, and potential mining across a highly prospective area.