Rocky Mountain National Park: Ypsilon Lake

Discover solitude in busy Rocky Mountain National Park on this 8.7-mile out-and-back leading to a pristine lake perched beneath the Mummy Range.

Big on scenery and small on crowds, this 9-miler swings from the Lawn Lake Trailhead to one of Rocky Mountain National Park’s lesser-visited landmarks. Heading north on Lawn Lake Trail, you’ll immediately begin climbing a ridge offering vistas of the Fall River and Horseshoe Park below.

The trail levels out as it begins tracing the Roaring River through a deep valley before leading to a Y-junction with the Ypsilon Lake Trail. Cross the river and turn left to begin the northern trek to the lake. The trail becomes steeper and rockier as you climb higher through thick pine forest.
Just before mile 4, the deep woods give way to Chipmunk Lake (10,680 feet). Continue north on the now level trail: Ypsilon Lake is less than 0.5 mile away. Before reaching the lake, you’ll pass a sidetrail to developed backcountry campsites. Upon reaching the lake, which is framed by Ypsilon Mountain and the cloud-scraping Mummy Range to the north, use a network of social trails to explore its pine-walled, boulder-strewn shorelines.

The lake is brimming with rainbow cutthroat trout, and fishing is especially fruitful in the lake’s shallow, southern section. For an alternate return to the trailhead, follow this GPS track of an off-trail route tracing the Roaring River. 

INFO For information on permits, current trail and camp conditions, and wilderness guidelines, go to

PERMIT A wilderness permit is required for all overnight camping in the backcountry. Reservations accepted ($20 administrative fee for permits during peak season).

CONTACT Rocky Mountain National Park, (970) 586-1206;

-Mapped by Chris Hood, Mountain Adventures

Trail Facts

  • Distance: 14.0



Location: 40.407369, -105.62604

From the parking lot just off Old Fall River Road, head north on the Lawn Lake Trail.


Location: 40.408791, -105.62638

At the fork, follow the sign pointing to Lawn Lake and Ypsilon Lake.


Location: 40.420161, -105.634897

At Y-junction, turn left to pick up the Ypsilon Lake Trail. Right fork leads to Lawn Lake.


Location: 40.438934, -105.662366

Pass Chipmunk Lake (10,680 feet). Ypsilon Lake sits less than 0.5 mile north.


Location: 40.441852, -105.664101

Turn right on this sidetrail to access an established campsite.


Location: 40.443211, -105.664594

Reach Ypsilon Lake (10,632 feet). Ypsilon Mountain and the Mummy Range tower to the north.

Lawn Lake Trailhead

Location: 40.407369, -105.625949


Location: 40.408709, -105.627151

Take the right fork toward Lawn Lake and Ypsilon Lake.

Trail Splits

Location: 40.420259, -105.634897

Turn left to pick up the Ypsilon Lake Trail.

Pushing North

Location: 40.428917, -105.649638

The trail becomes steeper and rockier as you climb higher.

Backcountry Campsite

Location: 40.441901, -105.663371

Camping is available in developed sites just south of Ypsilon Lake.

Chipmunk Lake

Location: 40.43888, -105.662191

Pass tiny Chipmunk Lake, framed by Ypsilon Mountain and Fairchild Mountain to the north.

Ypsilon Lake

Location: 40.443012, -105.664272

Follow social trails to explore the shores of Ypsilon Lake. At the lake's southeastern corner, a stream leads to picturesque cascades.