DURANGO — A federal appeals board has denied a challenge of southwest Colorado ski area’s plan to expand helicopter skiing.

The Durango Herald reports a U.S. Interior Department appeals board recently denied the challenge by San Juan Citizens Alliance, saying the alliance has no legal standing to file the claim against Silverton Mountain’s proposal.

In May 2017, the Bureau of Land Management approved a new five-year permit for Silverton Guides — an arm of Silverton Mountain — to swap some land for its heli-ski operation.

Critics said expanding heli-skiing would compromise prime backcountry ski areas and increase avalanche danger.

Silverton Mountain owners Aaron and Jenn Brill say the deal would help boost Silverton’s winter economy and would provide safer terrain for both heli-skiers and backcountry users.