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Rocky Mountain National Park

Rocky Mountain National Park: Lost Lake

Lost Lake. Stormy Peaks. These places represent their names well on this 19.4-mile out-and-back in the northeast corner of Rocky Mountain National Park.

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This 19.5-mile weekend retreat climbs 2,800 feet along the North Fork Big Thompson River to the cradle of Lost Lake. The initial stretch warms up the legs with a half-mile downhill before the climbing begins. The scenic trail passes buildings on a private inholdings (stay on trail), crosses footbridges in Roosevelt National Forest, and runs past homestead ruins in the Comanche Peak Wilderness before it enters Rocky Mountain National Park. Stop for the night at one of eight forest service campsites 2.3 to 3 miles from the trailhead, or continue to the National Park boundary for several widely-spaced permit-required campsites there.

The climb intensifies near mile 7 after cutting through an alpine meadow and passing the Lost Falls campground, one of four camping areas along the trail’s upper reaches. You’ll pass a spur trail to Lower Lake campsite. To continue, scramble over boulders on the climb to the mile-wide bowl between Stormy Peaks and Mount Dunraven.

Lost Lake is guarded by 12,000-foot peaks. Pick a flat rock along the lake’s eastern shore for postcard views of the snow-caps, or continue another quarter-mile around its south side to access the chilly water from a small sandy beach.

-Mapped by Kristy Holland

Hike Lost Lake

Rocky Mountain National Park ($12,
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Trail Ridge Road is closed from November to April. Check conditions for the east side of the park check Estes Park, CO (80517) Weather

$20 for entry to Rocky Mountain National Park; (970) 586-1242,

Visitor Information (970) 586-1206 (daily, 8 a.m. to 4:30 p.m. Mountain Time; recorded information after hours)
Trail Ridge Road Information Recorded Message 970-586-1222 (available 24 hours a day, updated when conditions and/or road status change)
Visitor Information for the Hearing Impaired (TTY): 970-586-1319 (daily, 8 a.m. to 5 p.m. Mountain Time)
Backcountry Office (970) 586-1242



Shell‎ 860 Moraine Ave. Estes Park, CO (970) 586-7867

Grab supplies or gear rentals (packs, bags, pads, and fishing gear) at Estes Park Mountain Shop, 2050 Big Thompson Ave., Estes Park, CO; (866) 303-6548.

The Country Market National Park Village 900 Moraine Ave. Estes Park, Colorado (970) 586-2702

Try a Mountain Mai Tai and the buffalo-and-bacon meatloaf at Peak-to-Peak American Grille, 451 South Saint Vrain Ave., Estes Park, CO; (970) 577-0577


Trail Facts

  • Distance: 31.2



Location: 40.475456, -105.460442

This route follows the North Fork Trail that begins on the south side of the parking area, near the toilet.


Location: 40.472855, -105.463585

Turn right at the T-junction toward Rocky Mountain National Park.


Location: 40.47279, -105.470001

Cross the North Fork Big Thompson River on this footbridge, the first of many along the trail.


Location: 40.479053, -105.47113

Stick to the trail as it enters private property. For the next quarter mile, you’ll pass summer-camp facilities including a horse barn, lodge and sport field.


Location: 40.482262, -105.474678

Turn left at T-junction following signs toward the National Park boundary and Lost Lake.


Location: 40.484741, -105.485169

Cross another footbridge and bypass the Forest Service campsites to your right. Eight campsites are scattered along the next half-mile of trail.


Location: 40.487663, -105.496674

At the western end of a meadow, you’ll pass these log-cabin ruins on your left.


Location: 40.494022, -105.508148

This section of the trail, high above the stream, is rocky with little of the lush riverbank vegetation common on other parts of the trail.


Location: 40.497753, -105.518578

The trail to the Boundary Creek campsite, the first site inside Rocky Mountain National Park. There are at least 7 other marked sites between here and Lost Lake.


Location: 40.497688, -105.530739

Stay to the right at the Y-junction to continue 4.4 miles to Lost Lake.


Location: 40.497189, -105.536919

A sign marks the half-way gain in elevation from the trailhead. From here, you have to climb just 1,400 feet to Lost Lake.


Location: 40.50032, -105.557472

Stay straight on the trail, bypassing the Lost Falls campsite. From this point, the uphill climb intensifies.


Location: 40.505417, -105.568123

Turn left at the T-junction, 2.1 miles from the lake.


Location: 40.505497, -105.57151

Cross the North Fork Big Thompson River, this is one of the few unbridged crossings, but several stepping-stones will keep your boots dry.


Location: 40.507267, -105.594887

Continue left at the Y-junction toward Upper Lost Lake campground and Lost Lake.


Location: 40.507526, -105.59938

At 10,714-feet, Lost Lake, is just below this area’s highest peaks and may take your breath away. Large rocks near its shore make great picnic spots.

Log Cabin

Location: 40.487556, -105.49633

These ruins are on the west end of an open field. Pass them on your left.

Boundary Creek Sign

Location: 40.497761, -105.518585

Boundary Creek Campsite

Location: 40.497974, -105.51831

Boundary Creek’s luxe campsite can accomodate 2-3 tens and comes complete with a privy, chopping block, fire ring, and easy access to the nearby stream.

Trail Sign

Location: 40.497719, -105.530747

The whole trail is well marked and informs hikers of distances and potential destinations.

Halfway Point

Location: 40.497192, -105.536964

This sign marks Halfway campsite and point where the trail has gained half the elevation to Lost Lake.


Location: 40.499393, -105.555191

Three miles from Lost Lake, a meadow offers glimpses of Stormy Peaks to the north and Mt. Dickinson and Mt. Dunraven to the south.


Location: 40.504715, -105.565361

During a rain or after heavy snow-melt, this waterfall can flood the trail’s footbridge.

North Fork Crossing

Location: 40.505497, -105.571465

Stepping stones provide dry passage across the North Fork of the Big Thompson River.

Snowy Climb

Location: 40.507572, -105.596451

This photo, taken in mid-June, shows potential snow cover on the upper reaches of the trail.

Lost Lake

Location: 40.507542, -105.599396

Large rocks on the east side of Lost Lake make great picnic spots.

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