If you’re up in Silverthorne, Dillon, or Keystone and don’t want to deal with I-70 Ptarmigan Peak trail is a good choice. The trailhead is right off of exit 205 on I-70(it’s signed once you get onto County Rd 2021). The trail starts off on an exposed hillside and jogs a bit on pavement until you get past the residential area. After the sign posting wilderness regulations(~0.75 miles in) the trail forms a shady loop to the wilderness boundary(~11,500 ft). The junction is just past an opening in the fence and under some power lines. The less traveled right-hand trail(2.5 mi) is steep and technical while the popular left-hand one(3.2 mi) is gradual and better maintained. The left one would be suitable for a cross bike though I would avoid weekends unless you like to dodge children. This would make a great ski touring trail during winter and it also appears to be used by horse people. I think the right-hand one may have been a 4WD road at one point and they put in berms to limit it to bikes. At any rate it’s a not particularly scenic trail, but would be fun to bomb down on a mountain bike. Many of the conifers on both trails are dead due to bark beetles, but you can’t avoid this today even in the national parks. The aspens and wildflowers mostly make up for it. At the wilderness boundary bikes, hang gliders, and leashless dogs are no longer allowed. From here you can continue on to Ptarmigan Peak(12,498 ft elev and another 1.6 trail mi) or you’re feeling extra perky hook into the Ute Peak, Ptarmigan Pass or South Fork trails. HELPFULHINTS — Latitude 40 maps has a useful Summit County trails topo map — There may be streams, but water treatment/filtering recommended — See photo for the unsigned trail junction
