Founded in 1935 through a partnership between Newmont Mining and brothers Tom and Bill Johnson, Tombill Mines Limited (TSX-V: TBLL) holds two of the eleven past-producing and producing mines in the Geraldton–Greenstone gold district, Ontario. The district, home to approximately 4,300 residents, lies about 225 km northeast of Thunder Bay and benefits from exceptional mining infrastructure.

Tombill’s portfolio consists of 74 royalty-free claims—including 60 fully owned patented claims, 9 patented mineral rights, and 5 leases—strategically positioned in the heart of the district:

• Main Group (51 patented claims): Borders the western edge of the Greenstone Gold Mine, straddling the Trans-Canada Highway.
• Ellis Group (5 patented claims): Located 4 km south of Geraldton.
• Tombill Old Mine Group (6 patented claims): Situated 10 km west-southwest of Geraldton.

The Tombill Old Mine produced 68,737 oz of gold at an average grade of 12.47 g/t between 1938–1942 and in 1955. The Talmora Mine, in the northeast Main Group, was constructed in 1942 but saw only minor production before closing in 1948, yielding 1,406 oz at 5.05 g/t.

The Greenstone Gold Mine—commissioned in May 2024 and bordering Tombill’s eastern boundary—is among Canada’s largest gold operations by annual production and grade. The broader Geraldton camp extends roughly 15 km along the Bankfield–Tombill Fault and the Trans-Canada Highway, encompassing multiple shallow and deep gold zones from the easternmost Greenstone open pit to the westernmost past-producing Key Lake/Jellicoe Mine.