Mogotes Metals Options Rio Tinto's Copper Cliff Gold-Copper Project in Montana

Mogotes Metals (TSXV: MOG) has signed an option-to-joint-venture agreement with Kennecott Exploration Company, a Rio Tinto subsidiary, over the Copper Cliff gold-copper porphyry project in Montana, U.S.A. Under the April 15, 2026 agreement, Mogotes can earn 51% by spending US$16 million on exploration over three years, and up to 60% with a further US$40 million by year six (Mogotes Metals, Apr. 15, 2026). Mogotes is based in Toronto, but the project is in the United States, not Canada (Mining Technology, Apr. 16, 2026).

Where Copper Cliff is

The project lies in Montana's Garnet Range, in Granite and Missoula counties, 13 km south-east of the town of Potomac and about 115 km from the historic Butte copper district (Mogotes Metals, project page). The old Copper Cliff mining district worked supergene ore on and off from the 1890s to the 1940s. Mogotes cites estimated historic output of about 110,000 lb of copper, 260 oz of gold and 570 oz of silver.

Kennecott discovered porphyry gold-copper mineralization at depth beneath the district in 2006 and drilled it until 2017. Nobody has explored the project since then (Mogotes Metals, Apr. 15, 2026).

What the Rio Tinto drilling shows

Mogotes has reviewed Rio Tinto's database of 25 holes totalling 32,000 m, seven of which cut the porphyry. The best intercept reported is hole 14CC0013: 1,252.5 m at 0.41 g/t gold and 0.34% copper from 665 m. That includes 305.2 m at 0.67 g/t gold and 0.59% copper from 859.3 m (Mogotes Metals, Apr. 15, 2026). Hole depths ranged from 655 m to 2,019.6 m.

Copper Cliff is a pre-resource, exploration-stage project. There is no mineral resource estimate. Mogotes has used the existing holes to define an exploration target footprint about 1,000 m deep and roughly 450 m by 300 m in plan, to guide its next drilling. The company says its verification of the Rio Tinto data is still ongoing.

Deal terms

The agreement is an option to form a joint venture, not a joint venture yet. Mogotes sole-funds the exploration; Rio Tinto does not put in capital during the earn-in (Mogotes Metals, project page):

• Stage 1 (51%): at least US$4.0 million in year one and a further US$12.0 million by the third anniversary, US$16.0 million in all, with at least 70% spent on drilling.
• Stage 2 (60%): a further US$40.0 million by the sixth anniversary, US$56.0 million in all.
• Kennecott back-in: within 90 days of the 51% earn-in, Kennecott can take its interest back to 51% by paying Mogotes US$32.0 million. Within 90 days of the 60% earn-in, it can move to 60% by paying US$140.0 million.

Some claims carry existing third-party net smelter return royalties.

What happens next

In a September 22, 2026 update, Mogotes said it plans 8,000 to 9,000 m of drilling at Copper Cliff, with the earliest start in November 2026. Permitting is still pending (Mogotes Metals, Sept. 22, 2026). Montana's season runs opposite to Mogotes' main project, Filo Sur on the Argentina-Chile border, where it plans up to 20,000 m in 2026-2027. It is also drilling up to 50,000 m at Beskauga in Kazakhstan.

Early-stage exploration carries high risk. The figures above are drill intercepts and spending commitments, not reserves or production.

For more, see our copper and United States coverage and our company profiles.

How we checked this: AI-drafted from the sources linked above and checked against them by our AI editor.