Alderfer 3 Sisters (A3S) is a decent sized JCOS park with recently added terrain and trails. It lies south of Evergreen. It is a little bit farther away, but is definitely worth the drive. There is a trail on the south side of the park that goes up to the top of Evergreen Mountain, and provides a nice climb with a sweet descent. Some of the rest of the park is decomposed granite track with some tight switchbacks and some fun, although relatively easy, technical terrain. The park can also be combined with the Denver Mountain Park Dedisse Park to the east, making for a longer ride, all on singletrack or old closed doubletrack. The park is a little higher in elevation, so sunburn comes quicker, and altitude (almost 9,000') affects the lungs, too.
There are 2 trailheads, both on the same road. Both now have bathroom facilies, although the west TH has a much larger parking lot and bathrooms.
You can make a nice stop at the top of The Brother, one of the other formations in the park. You can bike to the base of the 3 sisters, but to scramble up them, you will have to leave your bike. I recommend not scrambling on the rocks in hard biking shoes. Exposure exists!
Hidden Fawn East parking lot .5 mi +171' /-210' Flat, mostly open and exposed. Features wildflowers and mature pine stands.
Sisters East parking lot 1.2 mi +946' /-759' Strenuous, weaves through large boulders, technical biking.
Ponderosa Trail junction w/Sisters 1.7 mi +565 / -529' Pleasant, serves as a connector to many other trails.
Brother's Outlook Trail junction w/ Ponderosa 0.2 mi +69' / -0' Short hike to a great picnic site with a view.
Silver Fox North trail junction w/Ponderosa 0.5 mi +29' / -108' Meadow trail with a view of Elephant Buttes to north; wildflowers and fox.
Wild Iris Loop West parking lot 0.6 mi +65' / -52' Pleasant meadow trail. Close proximity to west parking lot
Evergreen Mtn. East East parking lot 1.8 mi 835' / -215' Gradual climb with view of the town of Evergreen.
Summit Trail junction w/ East and West Evergreen Trail 1.4 mi +200' /-345' View of Continental Divide.
Evergreen Mtn. West Trail junction w/Wild Iris 1.5 mi +398' / -64' Gradual climb, features granite outcropping.
Scenic View Trail junction w/Summit 0.2 mi +0' / -80' Old ranch house overlook.
Ranch View Trail junction w/Wild Iris 0.8 mi +3' / -223' Parallels Buffalo Park Road.
Wilmot Wilmot School 0.4 mi +151' / -0' Trail connector into park from the east side.
Bluebird Meadow West parking lot 0.3 mi +85' / -16' Meadow trail with wildflowers and wildlife.
Homestead Trail junction w/Silver Fox 0.5 mi +74' / -88' Short trail with original homestead, wetlands. Circles a great rock formation.
Mountain Muhly West end of Park 2.3 mi +350'/-484' Shady trail with rock formation views.
Bearberry West trail junction w/ Mountain Muhly 1.2 mi +156'/-136 A gentle and shady trail that passes a historic homestead.
Coneflower West trail junction w/ Mountain Muhly 0.2 mi +2'/-68' A short, sunny trail that follows a creek.
Dedisse Trail junction w/ Hidden Fawn 0.2 mi +0'/-17' Connector trail that ends at Evergreen lake.
My preferred ride is to ride everything in the north side of the park, then cross the road over and climb up Evergreen mountain from the east, then finish heading north and descending back to the THs. Sweet ride.
90% of the park is nice singletrack, the rest is old, closed doubletrack, which is basically 2 parallel singletracks.
To access the park, travel south of Evergreen, Colorado on Highway 73. Turn west on Buffalo Park Road, approximately 1 mile to the east parking lot. A second parking lot is located another 1/2 mile along Buffalo Park Road. Motorized vehicles are confined to the parking areas and roadways.
When to Bike
This park can hold late season snow and the south side (Evergreen Mountain side) can get muddy after rains/snow. Best times to ride are April-November. The sun can definitely be a factor at altitude. Most of the trails are fairly shaded.
Links & Other infoJCOS A3S Webpage