Ypsilon Lake, Lawn Lake Trailhead, Rocky Mountain National Park, Colorado

Ypsilon Lake - 8.75 miles

Lawn Lake Trailhead

Ypsilon Lake (10,632') in the Mummy Range of Rocky Mountain National Park

Ypsilon Lake (10,632') in the Mummy Range of Rocky Mountain National Park

Round-Trip Length: 8.75 miles
Start-End Elevation: 8,540' - 10,632' (10,762' max elevation)
Elevation Change: +2,092' net elevation gain (+2,358' total roundtrip elevation gain)
Skill Level: Moderate-Strenuous
Dogs Allowed: No
Bikes Allowed: No
Horses Allowed: Yes
Related Trails:

Ypsilon Lake - 8.75 Miles Round-Trip

Ypsilon Lake (10,632') is located 4.4 miles from Lawn Lake Trailhead in Rocky Mountain National Park. It lies in a confined, heavily wooded basin on the east slope of Ypsilon Mountain (13,514') and Mount Chiquita (13,069') in the Mummy Range.

Trail Map | Photo Gallery

Though much of the hike climbs arduously through nondescript forest, visitors will enjoy excellent cutthroat trout fishing at Ypsilon Lake and views of the Mummy Range from high points in the upper valley:

The Lawn Lake Trail climbs 534' to the level east bank of Roaring River with good views over Horseshoe Park on the ascent (1.0 mile : 9,074'). The trail turns north up level banks to the Ypsilon Lake Trail split (1.45 miles : 9,190').

The trail crosses over a passive section of river and turns sharply southwest for a steep climb through uniform lodgepole. Travel eases briefly at 2 miles and turns decisively northwest up a narrow, heavily wooded ridge.

Here the trail begins a moderately steep and rugged climb with few notable features until cresting at 3.8 miles (10,762') and dropping to Chipmunk Lake (4.0 miles : 10,682'), a small pond with views of Ypsilon Mountain and Fairchild Mountain (13,502').

The trail undulates on the valley floor to the cluttered NW shore of Ypsilon Lake (4.37 miles : 10,664'). Views are limited from this point, but you can follow social trails south to clearings along the outlet. A logjam makes crossing the outlet difficult, but you can follow the outlet downstream into a very pretty, more accessible meadow.

A social trail also leads to the north shore where the inlet drops through a steep, narrow chute. An unmaintained trail continues above the falls approximately .75 miles to Spectacle Lakes, located in a deep cirque beneath Ypsilon Mountain. Reaching them requires good endurance and basic scrambling skills.

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Interactive GPS Topo Map

Key GPS Coordinates - DATUM WGS84

  • N40 24.439 W105 37.564 — 0.0 miles : Lawn Lake Trailhead
  • N40 24.648 W105 37.722 — .55 miles : Steady climb over Horseshoe Park
  • N40 24.911 W105 38.013 — 1.0 miles : Level out on high bank over Fall River
  • N40 25.203 W105 38.085 — 1.4 miles : Ypsilon Lake Trail split

Worth Noting

  • The Mummy Range's middle and upper reaches generally face south-southeast, making them warmer and drier than comparable elevations in the Park. One result is a higher-than-average treeline, and the presence of lodgepole pine at elevations where spruce and fir would normally dominate.

  • On July 15, 1982, the Lawn Lake Dam - a 26' high earthen dam - failed. The dam released 674 acre-feet (219,724,000 gallons) of water at an estimated peak discharge rate of 18,000 cubic feet (134,640 gallons) per second down the Roaring River valley. Three people were killed and damages totaled $31 million. As a result, sections of the Roaring River's high gully walls are unstable today and prone to sudden collapse.

  • No horses are allowed beyond the 4.2 mile mark.

  • Ypsilon Mountain, Mt Chiquita and Mt Chapin are accessible from the Chapin Pass Trailhead.

Camping and Backpacking Information

Permits are required for all overnight stays. Fires are not permitted within Rocky Mountain National Park. Camp safely away from dead trees, as close as possible to the silver metal arrowhead posted at each site. Red arrowheads on trees provide additional guidance to each campsite from the main trail:

Upper Chipmunk Backcountry Campsite

  • The Upper Chipmunk site is located 4.2 miles from the Lawn Lake Trailhead at 10,640'. There are two individual sites and a privy. The sites are located northeast of the Ypsilon Lake trail between Chipmunk Lake and Ypsilon Lake in a dense pine forest. Water is available from the outlet of the pond or from Ypsilon Lake. The water is slow moving and a filter would be helpful in addition to your purification measures.

Backcountry Campsites en route to Lawn Lake and Crystal Lakes:

  • The Ypsilon Creek, Cutbank and Golden Banner sites are located on the west bank of Roaring River. A spur from the Lawn Lake Trail (2.9 miles, +1,092') crosses the river and forks with access to each:

Cutbank Backcountry Camspite

  • The Cutbank site is located 2.6 miles from the Lawn Lake Trailhead at 9,620'. There's one individual site with access to a privy. The site is located in a lodgepole forest on the west side of Roaring River. Water is available from Roaring River.

Ypsilon Creek Backcountry Campsite

  • The Ypsilon Creek site is located 2.9 miles from the Lawn Lake Trailhead at 9,560'. There's one individual site with access to a privy. The site is located in a lodgepole forest above the confluence of Ypsilon Creek and Roaring River on the west side of Roaring River. Water is available from both sources.

Golden Banner Backcountry Campsite

  • The Golden Banner site is located 2.9 miles from the Lawn Lake Trailhead at 9,600'. There's one individual site with access to a privy. The site is located in a lodgepole forest on the west side of Roaring River (.3 miles north of the river crossing). Water is available from Roaring River.

Lawn Lake Backcountry Campsite

  • The Lawn Lake site is located 6.2 miles from the Lawn Lake Trailhead at 10,987'. There are 4 individual sites and a llama-stock site, each with access to a privy. The sites are located in a spruce-fir forest on the north side of the lake, west of the Patrol Cabin. Water is available from the lake, but ideally taken from the inlet. Lawn Lake was once a man-enlarged lake, but the dam broke in 1982 causing considerable flooding downstream and forming the Alluvial Fan and Fan Lake. The lake now exists at its original level.

Fishing Information

Only catch and release fishing is permitted along the Roaring River, Lawn Lake, Crystal Lakes and Ypsilon Lake drainages.

  • A valid Colorado fishing license is required for all persons 16 years + to fish in Rocky Mountain National Park. No other permit is necessary, however special regulations may exist for each location. It's your responsibility to know and obey them. Regulations may change at anytime. Special restrictions may be put in place above and beyond what's listed here. Contact the Park before your trip for current information.
  • No bait or worms are allowed in catch-and-release waters.
  • Certain waters in the park with restored native fish populations are open year round during daylight hours, except as indicated. Use barbless hooks only. Any and all fish species taken must be immediately returned to the water unharmed.
  • Method of Capture: Each person shall use only one hand-held rod or line. A 'second rod stamp' is not honored in park waters. Only artificial lures or flies with one (single, double, or treble) hook with a common shank may be used. "Artificial flies or lures" means devices made entirely of, or a combination of, materials such as wood, plastic, glass, hair, metal, feathers, or fiber, designed to attract fish.
  • This does not include: (a) any hand malleable material designed to attract fish by the sense of taste or smell; (b) any device to which scents or smell attractants have been externally applied; (c) molded plastic devices less than 1.5 inches long; (d) foods; (e) traditional organic baits such as worms, grubs, crickets, leeches, minnows, and fish eggs; and (f) manufactured baits such as imitation fish eggs, dough baits, or stink baits. Fly fishers may utilize a two hook system, where one hook is used as an attractant.
  • While in possession of any fishing equipment, bait for fishing (insects, fish eggs, minnows, or other organic matter) or worms is prohibited. Children 12 years of age or under, however, may use worms or preserved fish eggs in all park waters open to fishing except those designated as catch-and release areas.
  • Use of lead sinkers (or other lead fishing materials) is strongly discouraged.

Rules and Regulations

  • A $20 Day Use Fee is required to enter Rocky Mountain National Park (or $30 for a 7 Day Pass).
  • Dogs are not permitted on hiking trails in Rocky Mountain National Park.

Directions to Trailhead

Ypsilon Lake is accessed from the Lawn Lake Trailhead in the north-central section of Rocky Mountain National Park. The Lawn Lake Trailhead is located 5.0 miles from the Beaver Meadows Entrance Station.

Directions: The Lawn Lake Trailhead is located 2 miles north of Highway 36 along Fall River Road.

From the Beaver Meadows Entrance Station, continue west on Highway 36 past Bear Lake Road to Deer Ridge Junction (3 miles). Turn Right at Deer Ridge Junction onto highway 34 and drive 1.9 miles to Fall River Road. Turn left onto Fall River Road and the Lawn Lake Trailhead will be immediately on your right-hand side.

Contact Information

Rocky Mountain National Park
Visitor Information:

Backcountry Office:

Campground Reservations:

Emergency Dispatch:

Trip Reports

There are no trip reports on this trail.


"The hike to Ypsilon Lake was beautiful. The trail isn't particularly difficult, but it is a steady climb for most of the 4.5 miles. One important note is that the bridge over the river is out, but can be crossed on one of a few fallen logs, if you have a good sense of adventure. It took us close to 5 hours round trip. (The river crossing and rain slowed us down!)"
Elizabeth  -  Colorado  -  Date Posted: July 8, 2015
"Wonderful trail, lightly traveled. We are from Wisconsin and it took about 5.5 round trip due to lack of experince with the elevation. Highly recommend it."
barbara  -  ypsilan  -  Date Posted: July 1, 2013
"Time will depend on your level of fitness, but I would allow a minimum of four hours for the round trip hike. There's some steady climbing on the way up, and rugged terrain as you near the lake. Nice secluded basin."
Dave  -   -  Date Posted: September 25, 2012
"I am just wondering how long it takes to complete this trail?"
dorothea  -  Aurora  -  Date Posted: September 25, 2012


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