Hallett Peak, Bear Lake Trailhead, Rocky Mountain National Park, Colorado

Hallett Peak - 10.0 miles

Bear Lake Trailhead

Large cornices form over Tyndall Glacier between Hallett Peak (12,713') and Flattop

Large cornices form over Tyndall Glacier between Hallett Peak (12,713') and Flattop

Round-Trip Length: 10.0 miles
Start-End Elevation: 9,475' - 12,713' (12,713' max elevation)
Elevation Change: +3,238' net elevation gain (+3,324' total roundtrip elevation gain)
Skill Level: Strenuous
Dogs Allowed: No
Bikes Allowed: No
Horses Allowed: No
Related Trails:

Hallett Peak - 10.0 Miles Round-Trip

Hallett Peak (12,713') is located 5.0 miles from Bear Lake Trailhead in Rocky Mountain National Park. This prominent summit along the Continental Divide stands over Chaos Canyon (south) and Tyndall Glacier (north). No maintained trail reaches Hallett Peak, however a well-established x-country route leads south from Flattop Mountain to its base, where a steep scramble continues up to the summit.

Trail Map | Photo Gallery

The .7 mile, 389' climb from Flattop to Hallett Peak offers remarkable views, and a rare chance to explore open tundra with relative ease.

Over 4 miles of the roundtrip distance runs above treeline across exposed terrain. Check weather before heading out and get an early start to avoid afternoon storms. Carry versatile layers and expect rapidly changing conditions throughout the day:

The trail rises quickly over Bear Lake to the Odessa Lake - Mill Creek Basin Trail split (.45 miles : 9,725'). It continues steadily in a spruce-fir forest to the Flattop Mountain Trail (1.0 mile : 9,965'), which steepens considerably on a rough, winding path.

Thick timber breaks at Dream Lake Overlook with good views up Glacier Gorge, and of Keyboard of the Winds on Longs Peak's west ridge (1.6 miles : 10,470').

Steady, steep climbing resumes in a thinning forest to Emerald Lake Overlook, which provides a commanding view over the gorge carved by Tyndall Glacier, one of five active glaciers in the Park (2.9 miles : 11,357').

Grades moderate as you transition through treeline (2.5 - 3.0 miles : 11,440'), where the forest gives way to thin bands of krummholz, willow, and forbs in the alpine tundra ecosystem.

Most alpine plants are perennials, some are dwarfed, but their blossoms may be full-sized. Flowering plants often have dense hairs on stems and leaves for wind protection, or pigments capable of converting sunlight into heat. Cushion plants avoid wind by growing close to the ground, and anchor themselves with long taproots.

Grasses and sedges take hold in richer soil beds. Non-flowering lichens can photosynthesize above 32 degrees, and outer fungal layers can absorb more than their own weight in water.

Grades steady on a well-cut, cairn-marked path into open tundra. The trail passes a hitchrack (3.9 miles, 12,135') with an up-close look at Tyndall Glacier and Hallett Peak.

The trail scales a perennial snowfield over the hitchrack and levels up to Flattop Mountain (4.3 miles : 12,324'), more aptly described as a long, level saddle on the Divide.

No sign marks Flattop, but the Flattop - Tonahutu Trail split is generally recognized as the summit. Turn south to reach Hallett Peak.

Even when clear of snow the route is frequently indistinguishable from the landscape; it may take a moment for your eyes to adjust and pick out the cairn-marked path.

The rocky trail edges around the top of Tyndall Glacier (4.55 miles : 12,318'), a useful landmark and beginning of the turn up to Hallett Peak. Cairns mark the way, but blend seamlessly into the talus.

If off course, improvise your way up - it's not very difficult to do so, and quite easy to find the established path when looking down on it from the summit (5.0 miles : 12,713').

Two wind shelters and a partially built third cap the summit. A map will help you identify neighboring Otis Peak (12,486'), Taylor Peak (13,153'), Longs Peak (14,259'), Notchtop Mountain (12,129'), Ptarmigan Point (12,363'), and portions of the Mummy Range, Never Summer Range and Grand Lake area. Turn northeast for good views of Tyndall Glacier and gorge, and southeast for Chaos Canyon and Lake Haiyaha.

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Interactive GPS Topo Map

Key GPS Coordinates - DATUM WGS84

  • N40 18.714 W105 38.760 — 0.0 miles : Bear Lake Trailhead
  • N40 19.048 W105 38.636 — .45 miles : Bierstadt Lake access trail split
  • N40 18.986 W105 39.187 — 1.0 miles : Flattop Mountain - Odessa Lake trail split
  • N40 18.753 W105 39.550 — 1.6 miles : Dream Lake overlook
  • N40 18.851 W105 39.776 — 1.95 miles : Rocky climb in thinning forest
  • N40 18.876 W105 39.896 — 2.25 miles : Begin transition through treeline
  • N40 18.872 W105 40.223 — 2.85 miles : Emerald Lake Overlook
  • N40 18.963 W105 40.351 — 3.5 miles : Grade moderates with views of Notchtop
  • N40 18.617 W105 41.059 — 3.9 miles : Hitchrack at base of perennial snow field
  • N40 18.535 W105 41.415 — 4.3 miles : Flattop Mountain Summit
  • N40 18.341 W105 41.468 — 4.55 miles : Tyndall Glacier sign
  • N40 18.229 W105 41.365 — 4.75 miles : Scramble through steep talus to summit
  • N40 18.183 W105 41.159 — 5.0 miles : Hallett Peak

Worth Noting

  • The Flattop Mountain Trail closely follows a route used by the Ute and Arapaho Indians to cross the Continental Divide and reach Grand Lake.
  • 4+ miles of the roundtrip hike to Hallett Peak run above treeline, and are highly exposed. Anticipate strong sun, wind, cool temperatures, and rapidly changing weather conditions. Carry versatile layers, sun protection, and ample water. Get an early start to avoid afternoon thunderstorms.

  • Though not technically an arete, Hallet Peak is very much like one. An arete occurs where two adjacent glaciers erode toward one another, leaving only a thin, steep rock ridge between their parallel U-shaped valleys.

  • Keep a safe distance from ledges and gorges, especially when covered by snow. It's difficult to tell where terra firma ends and cornices - which can be highly unstable - begin.

  • Krummholz - a German word meaning twisted wood - describes the stunted, irregular growth patterns of trees in the ecological transition zone between subalpine forests and alpine tundra. Poor soil, thin air, strong winds, and extreme weather limit and deform growth at these elevations.

Camping and Backpacking Information

There are no designated backcountry campsites on the Flattop Mountain Trail or the cross-country route leading to Hallett Peak, however there are several nearby sites accessible from the Bear Lake Trailhead.

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:

Sourdough Backcountry Campsite (10,628')

  • There is one designated site located 2.65 miles from the Bear Lake Trailhead, 60 yards north of the main trail on the south flank of Joe Mills Mountain. The site is located in a level spruce bench. One bear box is available. Water is available year-round from the North Fork of Mill Creek, Lake Helene and Two Rivers Lake.

Odessa Lake Backcountry Campsite (10,065')

  • There are two designated sites located 4.1 miles from the Bear Lake Trailhead in a spruce-fir stand east of Odessa Lake on the north side of its outlet stream. The sites are located just over the log bridge crossing of this stream. One bear box is available. Water is available year-round from Odessa Lake and its outlet stream.

Fern Lake Backcountry Campsite (9,530')

  • There is one group site and four individual sites located 5.1 miles and 5.3 miles from the Bear Lake Trailhead, respectively. Both are located in a mixed pine forest on the NE and NW sides of Fern Lake, respectively. Each has access to a bear box and privy. Water is available year-round from Fern Lake, its inlet and outlet streams.

Directions to Trailhead

Hallett Peak is accessed from the Bear Lake Trailhead in Rocky Mountain National Park. It's located 8.9 miles from the Beaver Meadows Entrance Station on Bear Lake Road.

Turn left onto Bear Lake Road just past the Beaver Meadows entrance station. The Bear Lake Trailhead is located at the end of this road. Additional parking and alternative access can be found at the Glacier Gorge Trailhead. This will add an additional 1 mile roundtrip to the hike.

Contact Information

Rocky Mountain National Park
Visitor Information:

Backcountry Office:

Campground Reservations:

Emergency Dispatch:

Trip Reports

There are no trip reports on this trail.


"We hiked the Hallett Peak Trail on Sunday, 6/10. Trail was clear up to the Dream Lake overlook. Once past the overlook, there are numerous snow drifts. These were pretty solid early in the morning but melty/slushy by early afternoon. We got through using nothing but trekking poles with no problems. Once past the tree line, it is totally clear except for immediately past the Flattop Mountain hutch rack. There is about a 300 foot snow field, followed by another 150 feet or so of mixed ice and mud. We got through it with no problems, and once past that, it is clear and bone dry all the way to the Hallett Peak summit."
Chris Vig  -  Kansas City  -  Date Posted: June 11, 2018
"Awesome Hike... Have completed it twice myself...once at 12 years old and once as an adult with my husband and two children. Beautiful scenery & many photo ops! Layers, snacks and lots of water a must! "
Likes2Hike  -  Huron, Ohio  -  Date Posted: November 10, 2013
"Solid trail all the way to the top with nice overlook views of Dream Lake and Emerald Lake along the way. You also get great views of Longs Peak. It's awesome getting to see over both sides of the Divide...it looks like one could easily just walk over to Grand Lake and Shadow Mountain Lake. We saw a few marmots, a couple of rock ptarmigan and a number of pikas along the way. "
Thunderable  -  Denver, CO  -  Date Posted: August 18, 2013
"I've gone up this twice. Don't turn around once you hit flattop take the extra hour or so to go up the Peak! The scramble makes it seem daunting at first but it finishes pretty quick. Bring your hiking poles for the long grinding descent. Can be done in 5 hours at hard pace"
Hans olavson  -  Austin 78701  -  Date Posted: August 13, 2012
"WOW! This is a strenous trail that once above the timberline crosses several snowfields and can be hard to stay on the path. It is not too hard to relocate the path once on top of flattop. The last few hundred yards can be a struggle, but the views...WOW!"
Rick Bright  -  Kingsport, TN  -  Date Posted: May 29, 2012


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