A skier near Vail's North Rim.

(Courtesy Flickr user Snow Snow/Creative Commons)

Alpine slides and hiking trails are luring more warm-weather visitors to Colorado’s mountain resorts, resulting in extra money for the federal government. That increase in summer travel is front and center in two ski areas’ expansion plans.

Most ski resorts operate on U.S. Forest Service land, and are required to send rent checks to the government based on annual revenue. The Denver Post reports an 11 percent uptick in money paid to the federal government during the 2015-2016 season.

One key to the shift is that some resorts like Vail now offer more options for summer visitors. Vail recently built attractions that include an alpine coaster. Skiing in the White River National Forest accounted for the largest portion of revenue: nearly $20 million of the $26 million in rent to Washington D.C.

In related news, the Aspen Skiing Co's plan to add on-mountain attractions to the Snowmass Ski Area received unanimous approval in its second reading earlier this week at a Snowmass Town Council meeting. It’s still awaiting final votes.

The Aspen Times reports the company plans to add attractions such as year-round or seasonal overnight camping facilities, including building mountain huts in areas such as Dikes, Slider and Turkey Trot and Elk Camp Saddle. The company is also adding a ropes course, new hiking and biking trails and an alpine coaster, where bobsled-like cars travel on tubular tracks in the forest.

Snowmass Mayor Markey Butler says it is important to have more hiking trails added along with biking trails to prevent conflicts between the two.

A summer "aerial adventure" tour that includes hiking trails and other features is part of an Arapahoe Basin environmental impact statement approved by the Forest Service last November for the Summit County ski area’s expansion.

The expansion will open up about 338 acres of skiing terrain in an area just west of the existing boundary known as the Beavers. Skiable acres will grow from about 1,000 to more than 1,300.