A proposal that could lead to a gold, platinum and silver mine in the Gros Ventre River drainage has Teton County commissioners “extremely concerned” about potential impacts to wildlife and scenery.

Teton County Commission Vice Chairman Leland Christensen made the comments in a July 16 letter to Bridger-Teton National Forest Jackson District Ranger Dale Deiter.

Maverick Exploration out of Ogden, Utah has submitted a plan to excavate up to 25 holes to conduct assay work and determine the feasibility for using a dry separation process for extracting gold, silver, and platinum from placer deposits along Cottonwood Creek on national forest land.

Cottonwood Creek is located roughly 18 miles up the Gros Ventre Road, which is unpaved for most of its length. The Gros Ventre River drainage is considered critical elk winter range and contains a pronghorn antelope migration route from Sublette County to Grand Teton National Park.

The drainage also contains three elk feed grounds and is considered important habitat for grizzly bears, mountain lions, wolves and a small population of sage grouse.

If the proposal is approved, Maverick Exploration would consider a full-scale mining operation on the 340-acre parcel.

In the letter, Christensen said the board “is extremely concerned with potential impacts from mineral exploration and development in the Gros Ventre River valley.”

Christensen raised questions about the legality of the claim, which lapsed in 2006 before being renewed, and said Deiter should look at the impacts of the full-scale operation, not just the test pits.

“Full development of the claims should be considered in connection with any proposed exploration, so that the claim holder has been placed upon notice as to the scope, extent and expense of required environmental mitigation in order to protect the wildlife and scenic resources on the Bridger-Teton and in the Gros Ventre River valley,” he wrote.

In an interview Wednesday, county  commissioner Hank Phibbs called the Gros Ventre drainage an important part of Teton County. “We would like to take a larger look at the picture,” he said. “We’re concerned about the actual mining.” There’s a difference between a couple of small holes verses full development, he said.

Phibbs also called the circumstances around the claim lapse “awfully confusing.”

Claim holder David Sturlin said Wednesday his father had health problems and let the claim lapse in 2006. The Bureau of Land Management required him to refile the paper work and the claim was reissued, he said.

Sturlin also said he appreciates the commissioner’s comments.

“I believe that the county has valid concerns,” he said. “There are different seasons that you would not mine because of wildlife migrations and things like that. We would be sensitive to those times. Basically I think we could come to a compromise that would be workable for all parties concerned.”

If a full-scale mine is warranted, the Forest Service and the Bureau of Land Management will come to an agreement on a level of disturbance that would be allowed, Sturlin said. A contractor would reclaim land as it was mined and the operation would not look like an open-pit mine, he said.

“I would never want to have that kind of an open eyesore in Teton County anywhere,” he said.

For the test holes, Sturlin plans to use a process called electrostatic separation, a combination air and electrically charged plates that separate metal particles from gravel. The process, he said, is more environmentally friendly than techniques that use cyanide or mercury to draw precious metals from the soil. Further, he said electrostatic separation works best in the absence of water, and wouldn’t affect any nearby creeks and rivers.

The initial test operation would likely start in September and would involve the use of a backhoe, a skid loader, two pickup trucks, a gravel screener, a generator, a house trailer and a gooseneck trailer.