Rocky Mountain National Park: Ypisilon Peak Loop

Connect two remote lakes on this challenging off-trail alpine adventure in Rocky Mountain National Park.

This three-day, 17.7-mile loop, featuring class 4 scrambles, nearly 6,000 feet of elevation gain, and off-trail route-finding, is not for the faint of heart. But the views of snow-speckled peaks stretching out to the horizon and the high-mountain solitude even in mid-summer make it a worthwhile journey for those who dare attempt it.

The first day is a mellow climb through mixed conifer forest to campsites at Ypsilon Lake. Get to bed early and rise at dawn on day two to avoid afternoon storms. Make your way up boulder fields and steep talus slopes to the southwest shoulder of Ypsilon Mountain. Traverse its rocky north side, before descending sharply on a scree field a saddle to the north. Clamber up another steep boulder field to Fairchild Mountain before descending gentler, meadowed slopes to find the trail from The Saddle, past Crystal Lakes, to Lawn Lake. Finish off the route on day three with an easy hike out on Lawn Lake Trail.

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 Rachel Zurer

Trail Facts

  • Distance: 28.5



Location: 40.407165, -105.626163

Begin at the Lawn Lake trailhead. There are latrines and a picnic area here, but no water, so tank up in town or at a visitor center.


Location: 40.414446, -105.633521

Horseshoe Falls


Location: 40.420025, -105.634764

Turn left on Ypsilon Lake Trail. The return route reconnects with the outbound route here.


Location: 40.419841, -105.635552

Cross the Roaring River on a log bridge.


Location: 40.425766, -105.645758

Forest cover opens up for a minute, but the trail continues to climb.


Location: 40.438945, -105.662577

Chipmunk Lake


Location: 40.440777, -105.664508

Turn right to access Upper Chipmunk campsite.


Location: 40.442007, -105.66365

Upper Chipmunk campsite


Location: 40.441325, -105.664714

Hitching post for horses


Location: 40.442799, -105.666032

Side trail to Ypsilon Lake heads right (east). Continue on path until it ends, then head west towards the basin below Ypsilon Mountain.


Location: 40.444023, -105.668714



Location: 40.445073, -105.672566

Cross above treeline. The terrain gets rockier as you hop across TV-sized boulders. Keeping heading west and uphill.


Location: 40.445412, -105.673982

Keep clamboring across a very steep boulder field as you head west up the north edge of the cirque below Ypsilon Mountain.


Location: 40.446037, -105.675425

Continue finding your way up and west across extremely steep, rocky, alpine terrain.


Location: 40.449331, -105.685515

You may have to cross snowfields and climb 3-5 foot stretches of class 4 rock on your way up the north east side of the cirque.


Location: 40.451095, -105.688026

Crest the southwest ridge of Ypsilon Peak. From here, traverse north across mostly-level talus for a welcome respite from the intense climbs.


Location: 40.460907, -105.683541

The respite is over at this saddle. Drop down the steep screen field, avoiding the precarious knife-edge ridge between Ypsilon and Fairchild Mountains.


Location: 40.462426, -105.678949

As the terrain levels, hop across boulders, avoiding snow fields. Keep an eye out for pikas amidst the rocks.


Location: 40.46396, -105.675087

Resume climbing the very steep south side of Fairchild. This section isn't technical but requires class 3 and 4 scrambling across very large boulders.


Location: 40.466288, -105.675741

From the edge of Fairchild's southwest shoulder, snag views of Desolation Peaks from a different angle before heading up to the northeast.


Location: 40.467715, -105.673628

The terrain gets even steeper. Keep heading west (nav tip: if you climb north too soon, you'll cliff out).


Location: 40.468412, -105.671598

Crest a broad ridge below Fairchild's summit. The tough climb is over. From here, the trip gets much easier.


Location: 40.468894, -105.668848

Drop packs and head east to summit 13,502-foot Fairchild Mountain.


Location: 40.468466, -105.664299

Fairchild Mountain: Take cover from the wind in the rock shelter. Backtrack to YML023 and turn right.


Location: 40.471208, -105.666718

After rounding the side of Fairchild, make your way down gentler, grassy slopes to the saddle below Hagues Peak.


Location: 40.480035, -105.657214

The trail resumes at this point on The Saddle.


Location: 40.4712, -105.635682

A side trail veers left (west) to Crystal Lakes. Continue the descent to Lawn Lake.


Location: 40.464686, -105.627623

Pass the Lawn Lake patrol cabin and the trail to campsites.


Location: 40.460836, -105.621561

Stay right on Lawn Lake Trail at the trail fork. Follow the path back to YML003 and continue straight to return to the trailhead.

Chipmunk Lake

Location: 40.438907, -105.662351

Pond near Upper Chipmunk

Location: 40.440807, -105.664229

Upper Chipmunk Campsite

Location: 40.442015, -105.663575


Location: 40.44414, -105.66882

Stick to the right and head up above this small cascade.


Location: 40.444204, -105.668996

Snow lingers in August below rugged granite rock faces to the north east of your route.

Rocky Trail

Location: 40.445045, -105.67249

The terrain gets rockier as you approach treeline.

Rock Knob

Location: 40.445047, -105.672531

Keep heading uphill and west around the side of this knob.

Lichen on streaked rock

Location: 40.445392, -105.673724

Views to the south

Location: 40.445412, -105.673912

Traversing a boulderfield

Location: 40.44542, -105.674105

Basin below Ypsilon Mountain

Location: 40.445424, -105.674202


Location: 40.446041, -105.675401

Colorado's state flower grows in the alpine zone as the terrain gets steeper. Keep heading up.


Location: 40.451802, -105.688278

Enjoy views of the snow-streaked Never Summer Mountains to the west.

Desolation Peaks

Location: 40.453618, -105.688357

The jagged, crumbly peaks to the north.

Knife Edge

Location: 40.460932, -105.683402

Avoid this scary ridge by descending to the east.

Screefield Descent

Location: 40.460914, -105.683258

Ypsilon Mountain

Location: 40.46396, -105.674829

Looking east towards Fay Lakes

Location: 40.464727, -105.674561


Location: 40.464848, -105.674551

Large rocks dot the alpine fairway as you climb towards Fairchild.

Desolation Peaks

Location: 40.466331, -105.675618

With unnamed lake below.

Views from below Fairchild Mountain

Location: 40.466388, -105.675604

Looking back towards Ypsilon Peak

Location: 40.46667, -105.675296

The knife-edge you avoided.

Boulder Piles

Location: 40.467727, -105.673521

From the top, the peaks never end

Location: 40.468458, -105.664294

Glacial Valley

Location: 40.468482, -105.664423


Location: 40.468474, -105.664541

Grand Lake

Location: 40.468482, -105.664262

Hagues Peak

Location: 40.471276, -105.666716

Looking down toward Hague Creek

Location: 40.471327, -105.66662

Gentler Slopes

Location: 40.477823, -105.660408

Views to the west

Location: 40.480594, -105.658929

The Saddle

Location: 40.480031, -105.657095

Looking back at Fairchild

Location: 40.475073, -105.643245

Crystal Lakes

Location: 40.475073, -105.643245

Lawn Lake

Location: 40.466413, -105.629107

Roaring River

Location: 40.45172, -105.626825