The Twin Sisters trail head parking lot is located 0.5 miles south of the Lily Mountain trail head on CO-7, across the street from Lily Lake, and is about 10 minutes from Estes Lake in Estes Park, Colorado. Parking is free even though the Twin Sisters trail cuts through Rocky Mountain National Park. The primary activity is hiking and backcountry permits are required for camping. Dogs, vehicles, and mountain bikes are not allowed on the trails. Horses are allowed on designated trails and there is an area large enough for horse trailers to park and turn around. The trail head does not have water or restrooms but Lily Lake across the street does. Cell phone service was nonexistent on the trail. The trail head parking lot is about 0.5 miles up and away from the street so do not be fooled into thinking that the parking lot directly across from Lily Lake is the best place to park for hiking Twin Sisters.
We hiked to the summit of Twin Sisters Peak on a warm day at the end of June. Twin Sisters trail is 3.7 miles one way with an elevation gain of ~2,300 feet; from 9,040 to 11,428 feet. It runs through both Rocky Mountain National Park and the Roosevelt National Forest. The trail starts with a dense forest canopy that offers shade and eventually rises above tree line.
The trail boasts a series of switchbacks that ease the ascent and provide views to the west that include Longs Peak. The trail is rocky in spots but free of any exceptionally difficult stretches.
This was one of only a couple of hikes we have done without our 2 1/2 year old daughter so, although it was a long hike, it felt easy in comparison to shorter hikes we have done with her on our back in a child carrier. The final stretch of trail is through a boulder field with an open landscape and unobstructed view to the north. At this point, we were beginning to feel fatigued and pre-picnic hunger was setting in. The difficulty of this trail was consistently moderate which allowed us to maintain a fun hiking rhythm.
On a sunny day, the panoramic view from the summit is breathtaking and an exceptional reward for a long hike. The trail leads up to the summit of the northwestern peak which is in the foreground of the following picture; Longs Peak is in the background. Hiking the 8.0 mile trail to the summit of Longs peak is one of our personal goals. We felt like the Twin Sisters hike, which is 3.7 miles one way, was a good practice hike since it is almost half the distance and elevation gain of the Longs Peak hike.
The previous picture and following pictures were taken from the southeastern peak that does not have an official trail to its summit, so we followed the Leave No Trace principle of traveling on durable surfaces (i.e., we jumped from rock to rock without stepping on the vegetation). Our scramble to the top of the southeastern peak is not recommended because it is precarious in a few spots. The northwestern peak summit via the designated trail was safe.
The following is the view to the south.
Scurrying around the summits were a couple of yellow-bellied marmots; one of which can be seen in the bottom left of the subsequent picture. These large squirrels rely on the subalpine vegetation near the summits so be sure to not step on any of the delicate vegetation growing on and around the rocks.
The following video was taken from the southeastern peak.
In sum, Twin Sisters is a day long hike that was challenging and rewarding but I imagine its difficulty and enjoyment depend heavily on the weather. The following are other RMNP/Estes Park trails we have enjoyed: