Isabelle Glacier, Brainard Lake Recreation Area, Indian Peaks Wilderness Area, Colorado

Isabelle Glacier - 8.75 miles

Brainard Lake Recreation Area

The approach to Isabelle Glacier

The approach to Isabelle Glacier

Round-Trip Length: 8.75 miles
Start-End Elevation: 10,515' - 12,025' (12,049' max elevation)
Elevation Change: +1,510' net elevation gain (+1,790' total roundtrip elevation gain)
Skill Level: Moderate-Strenuous
Dogs Allowed: Yes
Bikes Allowed: No
Horses Allowed: No
Related Trails:

Isabelle Glacier - 8.75 Miles Round-Trip

Isabelle Glacier lies in a saddle between Apache (13,441') and Shoshoni (12,967') peaks in the Indian Peaks Wilderness. The short hike to Lake Isabelle is one of the area's most popular, however crowds thin on the rugged trek up-valley to its glacial origin. Isabelle Glacier is one of 14 officially named glaciers in the Colorado Front Range.

Trail Map | Photos Gallery

Visitors will enjoy stunning alpine landscapes and a chance to explore the glacier on this highly rated trail:

A level path follows the north shore of Long Lake to the first of two connections with the Jean Lunning Trail (.2 miles : 10,524'). It undulates past a second Jean Lunning connection (1.2 miles : 10,674') to a clearing with a glimpse up-valley (1.6 miles : 10,716').

The trail steepens in a thinning forest to the Pawnee Pass Trail split (2.1 miles : 10,892'), and continues around a talus field on Isabelle Lake's north shore to its west inlet (2.4 miles).

The trail scales Isabelle's inlet falls to an alpine bench in the center valley (2.9 miles : 11,083'), followed by a similar push to a second (3.15 miles : 11,273'). The landscape opens with a revealing look at Isabelle in the northwest corner of the valley. Note that a smaller, unnamed glacier lies beneath Navajo Peak's 13,409' summit to the south.

Remain vigilant as the trail bends sharply south across the valley and loses clarity through marsh, willow, ponds and streams (3.2 miles : 11,295').

Conditions improve once on the valley's south side (3.45 miles : 11,360'), twisting steeply past treeline to a third bench at the foot of a glacial tarn (3.75 miles : 11,460').

The trail - now a rugged, uneven talus route marked sparingly by cairns - hugs the tarn's north side to a misty cascade (3.95 miles : 11,560').

Here it turns sharply north on a series of rugged, tightly-wound switchbacks; pay close attention to cairns, as the designated route offers the best footing through this terrain. The grade moderates and bends west on the final approach (4.2 miles : 11,915').

A direct, intuitive scramble negotiates the last talus field to Isabelle Glacier (4.35 miles : 12,025') . From these heights you'll enjoy up-close views of Navajo, Apache and Shoshoni peaks, and the finely sculpted rock pinnacles between them.

You can explore the glacier itself, though caution and light treading is a must on these unpredictable and occasionally unstable surfaces. A small tarn (snow covered and iced-over much of the year) lies below the glacier, an interesting excursion if conditions permit.

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Interactive GPS Topo Map

Key GPS Coordinates - DATUM WGS84

  • N40 04.674 W105 35.077 — 0.0 miles : Long Lake Trailhead
  • N40 04.550 W105 35.220 — .2 miles : Jean Lunning Trail junction #1
  • N40 04.223 W105 36.083 — 1.2 miles : Jean Lunning Trail junction #2
  • N40 04.167 W105 36.716 — 1.85 miles : Begin moderate switchbacks
  • N40 04.225 W105 36.875 — 2.1 miles : Lake Isabelle and Pawnee Pass Trail junction
  • N40 04.116 W105 37.406 — 2.6 miles : West end of Lake Isabelle
  • N40 04.028 W105 37.671 — 2.9 miles : Tier 1 of inlet falls
  • N40 03.930 W105 37.860 — 3.15 miles : Tier 2 of inlet falls - cross valley
  • N40 03.753 W105 37.919 — 3.45 miles : Reach south side of valley
  • N40 03.719 W105 38.162 — 3.75 miles : Edge of glacial tarn
  • N40 03.734 W105 38.300 — 3.95 miles : Switchbacks @ cascade above tarn
  • N40 03.793 W105 38.367 — 4.1 miles : Continue on switchbacks above tarn
  • N40 03.790 W105 38.451 — 4.2 miles : Cross stream
  • N40 03.799 W105 38.564 — 4.35 miles : Isabelle Glacier

Worth Noting

  • Isabelle Glacier was named by Fred Fair, a Boulder City engineer who discovered the glacier in the early 1900s. He named both it and Lake Isabelle after his wife. When he died in 1935, his ashes were scattered over Isabelle and Fair glaciers.

  • Isabelle Glacier forms the headwaters of South Saint Vrain Creek.

  • Snow may linger on the trail well into summer, compromising safety and routing. Check with the Forest Service for current conditions and trail information.

  • Get an early start to avoid afternoon thunderstorms that are difficult to see coming over the Continental Divide. When storms are imminent, get below tree line as quickly as possible.

Camping and Backpacking Information

  • Permits are required for all overnight campers June 1 - September 15. Permits are required year-round for day and overnight use by large groups (8+) and organizations (scouts, churches, schools, hiking clubs, etc).

  • Campfires are prohibited east side of the Continental Divide, as well as Caribou Lake, Columbine Lake, Gourd Lake, Crater Lake and in the Cascade Creek drainage above Cascade Falls.

  • Group size is limited to 12 people or people and packstock combined.

  • Camping is prohibited in the Four Lakes Backcountry Zone (Mitchell, Blue, Long, Isabelle) May 1 - Nov 30.

  • Camping is permitted only at designated campsites in the Diamond, Jasper, Crater and Caribou Lakes Backcountry Zones.

  • Camping is prohibited within 100' of lakes, streams and trails.

  • Packstock is prohibited in the Four Lakes Backcountry Zone, in the Cascade Backcountry Zone above Cascade Falls, and on the Diamond Lake Trail #975.

Rules and Regulations

  • There is an $11 fee to enter the Brainard Lake Recreation Area. Use the self-service pay station if no attendant is on duty. Fees, Parking, Pet, Camping and Trespassing regulations are strictly enforced.

  • Dogs must be leashed at all times on trails within the Brainard Lake Recreation Area.

Directions to Trailhead

The Long Lake Trailhead is located within the Brainard Lake Recreation Area off of CO 72 (12 miles north of Nederland, just north of the town of Ward).

From Highway 72, turn west on Brainard Lake Road. In 2.6 miles you'll reach a pay station. Use the self-service pay station if no attendant is on duty. Continue another 3.2 miles on the paved road to the Long Lake Trailhead. This road may be closed at the halfway point from late October through late June or early July (depending on snow).

Long Lake can also be reached via the Niwot Cutoff Trail from the Niwot Cutoff Trailhead near the Niwot Mountain Picnic Area on the west end of Brainard Lake.

Contact Information

Boulder Ranger District
2140 Yarmouth Avenue
Boulder, CO 80301

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