Lonoke-based U.S. Rare Earths said Thursday it plans in May to start drilling for core samples in the Sheep Creek area on Lemhi Pass in Montana.
"It's such a promising site," said company President Dan McGroarty. "The geology over eons has basically tipped up in a way that what it's done is expose layers that would have been far below the surface."
He also said the area contains extensive records from previous geologists searching for precious metals.
On the Idaho side, the company has been drilling in the Salmon-Challis National Forest. It's unclear what the company has found.
"We know from geology that there are rare earths out there," said Russ Bjorklund, Salmon-Challis National Forest minerals program manager. "No one has ever really started looking out there (before) because it costs a heck of a lot of money."
Rare earth minerals are used in consumer electronics and other products. Rare earths aren't scarce, but few places exist with enough concentrations to mine profitably, and they are difficult to isolate in a purified form and require advanced technology to extract.
Last year, the World Trade Organization created a panel to evaluate China's rare earth exports after the U.S., the European Union and Japan complained about the curtailment of Chinese sales of rare earth minerals. That has led to increased interest in developing U.S. sources for rare earth minerals.
Virginia Gillerman, an economic geologist for the Idaho Geological Survey, said Idaho has large deposits of rare minerals such as neodymium, lanthanum and cerium.
"Like any mining project, a company has to prove there is enough in the ground to make it economically worthwhile to extract - and that they can extract it efficiently," Gillerman said.
Bjorklund said that U.S. Rare Earths has submitted three plans to the Salmon-Cahllis National Forest. Two have been approved, and drilling is taking place on one of them.