Deep mine exploration proposed near Lake Mary Ronan
Laura Lundquist
(Missoula Current) The state of Montana is reviewing a exploration license for another company wanting to join the rush to mine Montana, this time on private land west of Lake Mary Ronan.
On Tuesday, the Montana Department of Environmental Quality published a draft environmental assessment of the Crossover Project proposed by WRH Nevada Properties on July 1. The Crossover Project is on private land about 10 miles due west of Lake Mary Ronan and about a mile north of the Flathead Reservation. DEQ is accepting public comment on the environmental assessment until Aug. 27.
WRH Nevada is proposing to drill at four sites mostly south of Crossover Road. Three of the drill holes could go as deep as 3,500 feet and one would be 4,000 feet deep. The drill sites are approximately 600 yards apart.
Once DEQ approves the exploration project, WRH Nevada would work up to 24 hours a day, seven days a week, with the aid of artificial lighting. To cool the drills, workers would use up to 16,000 gallons of water a day, which would be purchased from the City of Hot Springs and transported 20 miles north along Highway 28 using 2,000-gallon trucks. That would require eight roundtrips a day.
The drill sites parallel an ephemeral stream within a 1.41-square-mile sub-basin of the Mill Pocket Creek-Little Bitterroot River watershed. One site sits 50-100 feet uphill from the stream. The Little Bitterroot River eventually feeds into the Flathead River. The EA says it’s unknown whether the drill holes will encounter groundwater “due to the lack of existing water wells within the immediate project area.”
It’s not clear when work would start, but the company anticipates being done by September 2027 with reclamation completed a month and a half later.
On its website, WRH Nevada Properties calls the Crossover Porphyry Target project one of its “most advanced projects.”
“WRHNP completed an (induced polarization-magneto telluric) survey to follow up on prior magnetic and geophysical data that revealed classic porphyry signatures. The new IP-MT results have defined clear drill targets, which we plan to test during the 2026 season. This project lies directly adjacent to the ongoing exploration efforts by Ivanhoe Electric (under their earn-in agreement with Brixton Metals), where they are actively pursuing a copper porphyry system. WRHNP views this as a district-scale opportunity with significant untapped potential,” the company wrote on its website.
Copper porphyry deposits are the world's primary source of copper and can also be a source of other metals such as molybdenum, silver, and gold, according to the U.S. Geological Survey. The Berkeley Copper Mine in Butte mined copper porphyry deposits.
The land near the Crossover Porphyry Target has several existing and historic mining sites dating back to the mid-19th century, particularly in the Hog Heaven mining district east of the Crossover project. Two miles northeast of the Crossover project, the Flathead Mine has been extensively disturbed since the 1930s after silver ore was first discovered in 1913.
For the past six years, Canada-based Brixton Metals, operating as Brixton USA Corporation, has been exploring near the Flathead Mine for silver, gold, lead and copper in the Hog Heaven Project where DEQ is reviewing additional proposed activity, which would involve 27 drill holes on 10 drill pads.
WRH Nevada Properties also says it acquired new exploration data that extends beyond its 830,000-acre deeded mineral holdings in Western Montana “to encompass a broader, highly mineralized region.”
The 830,000 acres of mineral rights that WRH Nevada owns lies beneath the timberlands now owned by Green Diamond but previously owned by Weyerhaeuser. Because of those mineral rights, WRH Nevada tried to block a popular conservation easement that keeps much of northwestern Montana undeveloped and maintains working timberlands.
In 2024, WRH Nevada tried to stop Green Diamond and the state of Montana from finalizing the 32,900-acre Great Montana Outdoors Conservation Easement in the Cabinet and Salish Mountains west of Kalispell.
Even though Montana law says mineral rights owners “have the right to reasonable use of the surface, regardless of whether or not the surface owner grants permission,” WRH Nevada sued Fish, Wildlife & Parks, the FWP commission, the Trust for Public Lands and Green Diamond to stop the easement, saying the easement would prevent them from exploiting their mineral rights. FWP attorneys said conservation easements didn’t go that far.
In order to finalize the conservation easement, the Montana Land Board inserted language into the deed restating that the easement doesn’t stop exploration of the land’s mineral rights. The easement was approved in December 2024.
The Crossover Project is not on any of the Green Diamond lands, which are farther north.
Those wanting to comment on the exploration environmental assessment should send online comments to deqmepa@mt.gov or mail comments to: Field Services and Technology Section, Mining Bureau, Department of Environmental Quality, 2401 Colonial Drive, Helena, MT 59601.
Contact reporter Laura Lundquist at lundquist@missoulacurrent.com.