Open space officials on Thursday unveiled an ambitious plan to develop more than 16 miles of trails and protect roughly 300 acres of habitat in the Sky Mountain Park area, formerly known as the Droste property.

Pitkin County partnered with the state and local governments to purchase, for $17 million, an 845-acre parcel of land between Aspen and Snowmass Village in 2010 from the Droste family. The plot is the centerpiece of the Sky Mountain Park, for which recreation planning efforts have been underway for months.

A trail development and habitat restoration plan was unveiled Thursday night at a public open house in Snowmass Town Hall.

The plan will be reviewed by local open space boards, the Pitkin County commissioners, and the Aspen and Snowmass Village councils this spring. County land steward Gary Tennenbaum said he is hoping to have a trail and management plan adopted this spring, with construction on some trails beginning in May.

Highlights of the plan include a 1.5-mile single-track trail running up the Shale Bluffs side of the mountain park. Tentatively named “Shale Trail,” it would provide an alternative to the Jeep road that currently provides access to the Skyline Ridge Trail from the Aspen side.

Tennenbaum highlighted the views available from the potential trail site.

“They are astounding,” he said.

Skyline Ridge was the only trail open in the park last summer.

“We thought this would greatly increase users from the Aspen side,” said Aspen parks and recreation manager Jeff Woods of the potential trail.

The trail crosses land owned by the Aspen/Pitkin County Airport, and would require airport approval.

A trailhead parking lot also is proposed near the bottom of the jeep road. This past summer there was no parking available at the trailhead on the Aspen side. The closest parking was at Buttermilk. Planners are proposing a second trailhead parking lot at the bottom of the existing Viewline Trail, on the Snowmass Village side of the former Droste property.

The “Shale Trail” would connect to a proposed 2.3-mile single-track trail running from Brush Creek Road to the point on top of the property’s prominent ridge where the existing Skyline Ridge Trail meets the jeep road. Planners are proposing to name it “Cozyline Trail.”

There is one trail proposed to run down the prominent north-facing slope of the property, from Skyline Ridge toward Brush Creek Road. That 3.6-mile single-track trail, tentatively named “Ditchline Trail,” would run down the slope and then follow a former ditch back to the bottom of the Viewline Trail on the Snowmass Village side.

The creative route of that trail was the result of public meetings held this fall with recreation groups, Tennenbaum said.

Also part of the proposal is a 2.5-mile single-track trail connecting the Rim Trail to Brush Creek Trail, creating a new loop.

Overall, the proposed trail lines aim to maintain a relatively gentle slope, with most of them below an 8 percent grade.

Which of the trails would be built first has yet to be determined and will depend largely on public input in coming months, Tennenbaum said.

All of the 16.5 miles of trail proposed for the area could be built in the next two or three summers, he added.

“It will definitely take a few years,” Tennenbaum said.

The plan includes a continued ban on dogs in the mountain park.

The habitat protection part of the proposal includes large swaths of preserved areas and treatment plans. Most notably, the plan includes no trail development on the south-facing slope below the Skyline Ridge Trail, on the Aspen side of the park. The area is considered critical elk and deer habitat.

“I think the preservationists are going to be pleased,” Woods said.

The plan includes thinning of decadent, overgrown shrub oak on 296 acres of the former Droste family plot. A biological survey of the area released last fall recommended preserving large chunks of habitat. The plan aims to do that, bisecting the north side of the former Droste plot with one trail — the proposed “Ditchline Trail — on that side.

The silverleaf milkvetch, a rare plant discovered throughout the property, would be the focus of six separate study areas. Trails would be cut to avoid areas where the plant is most prevalent.

Timing of trail construction and the scope of habitat work will largely depend on whether the county can win a large grant from the Greater Outdoor Colorado (GOCO) fund. GOCO contributed $2.5 million to the government purchase of the Droste property in 2010. The county’s application for the new grant is in the works.

Maps of the plan are available for public view and comment at www.aspenpitkin.com/Departments/Open-Space-Trails/ [1].

Another open house on the plan is scheduled for Feb. 1 in the Rio Grande Room in Aspen.

andrew@aspendailynews.com [2]