Forest Service taking comments on Idaho open-pit mine plan

The U.S. Forest Service is taking comments and holding a public meeting on proposed exploratory drilling for an open-pit molybdenum mine being considered in Boise National Forest in Idaho.

The meeting comes two years after a federal judge rejected a previous Forest Service environmental assessment as lacking information about a rare plant called Sacajawea's bitterroot.

The judge ruled in a lawsuit brought by environmental groups that the Forest Service didn't adequately consider the exploratory drilling's impact on the plant because officials hadn't taken into account a 2014 wildfire that tore through the area.

Shortly after the ruling, another large wildfire scorched about half of the proposed drilling area.

The Forest Service said its most recent environmental assessment takes into account those wildfires when considering the project's effects on Sacajawea's bitterroot.

Environmental groups that filed the initial lawsuit didn't respond to messages left Wednesday or declined to comment.

Molybdenum is a metal with a high melting point that's used to make electrodes, missile and aircraft parts, and has some uses in the nuclear power industry.

The exploratory drilling is being considered by Idaho CuMo Mining Corp., a subsidiary of Vancouver, British Columbia-based American CuMo Mining Corp. It says the area about 45 miles (72 kilometers) northeast of Boise contains the largest unmined deposit of molybdenum in the world.

The proposed plan would allow about 13 miles (21-kilometers) of new roads and the use of about 5 miles (8 kilometers) of existing unauthorized roads to reach up to 122 drill pads in the 2,885-acre (1,200-hectare) site.

The Forest Service says Sacajawea's bitterroot is only found in central Idaho, growing at elevations from 5,400 feet (1,600 meters) to 9,500 feet (2,900 meters). About two dozen populations are known to exist, with about 75 percent of those in Boise National Forest.

The Forest Service has also identified scattered populations in Payette, Sawtooth and Salmon-Challis national forests.

The agency looked at groups of plants within the drilling area that occurred at what's considered near the plant's lower elevation boundary. The agency also looked at six sites within a 10-mile radius of the project area but outside the project area, finding "the overall population having excellent vigor."

The agency said clusters of the plants had likely adapted to their unique growing area, making them genetically distinct, including those in the proposed drilling area.

A public meeting on the latest environmental assessment is set for Jan. 9 in Boise, and the Forest Service is taking public comments through late January.