Temperatures are warming but mountain bikers must cool their jets for a few more days before some prime upper-valley trails open.

Sky Mountain Park opens Tuesday, providing a green light for the Airline, Cozyline, Skyline Ridge, Deadline and Viewline trails. Even though the weather is forecast to be ideal this weekend, Pitkin County Open Space and Trails believes it is important to stick with its historic opening dates, program director Gary Tennenbaum said.

For one thing, the agency wants to be consistent and not change dates from year to year. More importantly, the closures were set for the benefit of wildlife, he said. Pitkin County consulted with Colorado Parks and Wildlife to set the closure dates.

“May 16 is a pretty solid date of giving the animals enough time to migrate higher,” Tennenbaum said earlier this spring. Elk migrate through Sky Mountain Park to get to calving grounds on Burnt Mountain.

In addition to Sky Mountain Park, two popular trails on the west side of Brush Creek Road will open Tuesday: the Rim Trail North and Seven Star routes.

The Glassier Open Space on the Crown in the El Jebel area also opens Tuesday.

Poaching the trails overseen by Pitkin County Open Space and Trails is punishable by a $100 fine.

Wildlife closures will remain in effect until June 21 for several other trails in Snowmass Village. Tom Blake, Sequel, Anaerobic Nightmare and Government east of the Elk Camp work road are closed for elk calving.

The town of Snowmass Village takes violations of closures seriously and tracks activity in the area.

“We issued two tickets on North Rim Trail for people going over signed gates that are locked,” said Laurie Smith, an officer with the Animal Services Department. Two additional ticket are being written.

In the Burnt Mountain area between Snowmass and Buttermilk ski areas, Snowmass officers team with the U.S. Forest Service, Aspen Skiing Co. and Colorado Parks and Wildlife to make sure people stay out. Wildlife cameras used to monitor the species using Burnt Mountain also capture images of trail poachers. Those images are used for prosecution.

Smith said the wildlife cameras make it clear the area is heavily used by critters.

“We see elk cows with calves. We see does with fawns. We see bears with cubs of the year. We see moose,” she said.

Her department would prefer to see the closure through June, but human pressure to use the trails is too strong by late June, so the 21st was a compromise.

“We get significant (human) use and the wildlife moves out,” Smith said.

A handful of trails aren’t affected by wildlife closures in Snowmass Village, including Highline, Lowline and Rim Trail South.

Snow levels and the amount of water and mud on trails affect when many trails on U.S. Forest Service land open in Hunter Creek Valley and Smuggler Mountain.

Downvalley trails such as the Red Hill network and the Crown via Prince Creek Road have been dry and open for weeks.

scondon@aspentimes.com