Blue Lake
Blue Lake is a high alpine cirque lake at about 11,320 feet in the Indian Peaks Wilderness, reached on the Mitchell Lake Trail past Mitchell Lake, sitting below Mount Toll on the Continental Divide about 5 miles round trip from the trailhead.
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Blue Lake quick facts
- Distance
- Roughly 5 miles round trip from Mitchell Lake Trailhead. The Forest Service describes about a half mile to Mitchell Lake, then another 1.5 miles on to Blue Lake; GPS trackers report closer to 5 to 6 miles for the full out-and-back.
- Elevation gain
- Roughly 850 to 1,000 feet. The Mitchell Lake Trailhead sits at 10,500 feet, and the trail climbs steadily, with a steeper pitch above Mitchell Lake.
- Lake elevation
- About 11,320 feet, at tree line in a glacial cirque below the Continental Divide.
- Difficulty
- Moderate to strenuous. It's higher, longer, and rockier than the walk to Mitchell Lake, with thin air and a rugged final stretch.
- Access
- A timed-entry reservation is required to drive in during summer, one per vehicle, booked on Recreation.gov. The main gate opens in mid-June; the upper trailheads (Mitchell Lake, Long Lake) aren't scheduled to open until about July 1. Off-season you can park at Brainard Gateway Trailhead, two miles out, with no reservation but a $10 day-use fee.
- Dogs
- Allowed on a hand-held leash at all times from May 1 through November 14. From November 15 through April 30, dogs are limited to the Brainard Lake and Lefthand Park Reservoir roads.
- Permits
- No day-use permit for individual day hikers. Organized groups need a permit year round. Overnight camping requires an Indian Peaks Wilderness permit (June 1 through September 15), and camping is prohibited in the Four Lakes zone from May 1 through November 30. Bear canisters are required near trailheads year round.
- Best season
- Mid-July through September, once the upper trailheads open and snow clears the cirque. Snow lingers late up here, and ice can rim the lake into early summer.
Blue Lake at a glance
Blue Lake sits high in a glacial cirque at the far west end of the Brainard Lake Recreation Area, inside the Indian Peaks Wilderness. You reach it on the Mitchell Lake Trail, following the same path that leads to Mitchell Lake and then climbing on above tree line into an open basin of tundra and talus. The lake fills the bowl below Mount Toll, the cone-shaped pinnacle on the Continental Divide, with Pawnee Peak and Mount Audubon framing the rest of the skyline. It's one of the payoff destinations of the whole area, and a real step up from the gentler walk to Mitchell Lake.
How far is it, and how much climbing?
From the Mitchell Lake Trailhead, the Forest Service describes about a half mile of good trail to Mitchell Lake, then another 1.5 miles that climbs more steeply and follows the creek up an open valley to Blue Lake. Most GPS trackers report the full out-and-back at somewhere between 5 and 6 miles. The trailhead sits at 10,500 feet and the lake is around 11,320 feet, so you're gaining a few hundred feet of net elevation over rolling, rocky ground, which at this altitude feels like more. Call it moderate to strenuous and give yourself a half day.
Getting there: timed-entry reservation and season
Brainard Lake Recreation Area uses a timed-entry reservation system in summer, and vehicles need a reservation booked on Recreation.gov, one per vehicle. The main gate opens in mid-June, but the upper trailheads that reach Blue Lake, Mitchell Lake and Long Lake, aren't scheduled to open until about July 1, once the snow melts back. The gate closes in mid-October. Outside the reservation season you can still park at Brainard Gateway Trailhead, about two miles below the lake, with no reservation but a $10 day-use fee, and walk or ride in from there.
Wilderness rules and permits
The trail crosses into the Indian Peaks Wilderness right near the bridge over Mitchell Creek, so wilderness rules apply. Motorized equipment and mechanized transportation, including bikes, are not allowed. Individual day hikers don't need a separate day-use permit, but organized groups need a permit year round, and anyone camping overnight needs an Indian Peaks Wilderness permit for June 1 through September 15. Camping is prohibited in the Four Lakes Backcountry Zone, which includes this trail, from May 1 through November 30, and bear canisters are required near the trailheads year round.
Dogs on the Blue Lake trail
Dogs are welcome, but they must be on a hand-held leash at all times from May 1 through November 14, both in the recreation area and out on the wilderness trail. The off-season rule is stricter: from November 15 through April 30, dogs are limited to the Brainard Lake and Lefthand Park Reservoir roads and are not allowed on the trails. There's no voice-and-sight option here the way there is on some Boulder foothill trails.
Best season and time to go
Mid-July through September is the window. Before then, the upper trailheads are usually still gated and the cirque holds snow, which makes the upper trail easy to lose and can leave ice rimming the lake into early summer. Whenever you go, start early. Afternoon thunderstorms build fast over the Divide in summer, and you don't want to be standing in an open alpine basin when the sky turns. Bring layers even on a warm morning; it's cold and windy up here when the weather shifts.
Nearby trails and guides
- Brainard Lake: the recreation area itself, with the reservation system, gate season, and easier lakeside options.
- Mitchell Lake: the shorter, gentler lake on the same trail, a good turnaround if Blue Lake feels like too much.
- All hikes in Boulder: the full hiking hub, sorted by difficulty.
Recommended nearby
A few local spots we'd point a Blue Lake day toward.
[CLIENT SLOT: featured gear or rental shop near Brainard Lake]
[One honest line: layers, microspikes, or a bear canister for the alpine.]
[CLIENT SLOT: featured cafe in Ward or Nederland]
[One honest line: coffee or a warm bite on the drive up or down.]
[CLIENT SLOT: featured guide or fly shop near Indian Peaks]
[One honest line: a guided hike or the alpine fishing report.]
Blue Lake FAQ
How long is the hike to Blue Lake?
It's about 5 miles round trip from the Mitchell Lake Trailhead. The Forest Service describes roughly a half mile to Mitchell Lake, then another 1.5 miles on to Blue Lake; GPS trackers commonly report 5 to 6 miles for the full out-and-back. Plan on climbing steadily from 10,500 feet to about 11,320 feet at the lake.
Is Blue Lake harder than Mitchell Lake?
Yes. Mitchell Lake is a short, fairly easy walk through the woods. Blue Lake keeps going another 1.5 miles and climbs more steeply above Mitchell Lake, ending in an open, rocky alpine cirque at tree line. Between the added distance, the thinner air, and the rougher final stretch, it's moderate to strenuous rather than easy.
Do you need a reservation to hike Blue Lake?
To drive in during the summer season, yes. Brainard Lake Recreation Area uses a timed-entry reservation system, and vehicles need a reservation booked on Recreation.gov (one per vehicle). The main gate opens in mid-June, and the upper trailheads that reach Blue Lake, Mitchell Lake and Long Lake, aren't scheduled to open until about July 1. Off-season, you can park at Brainard Gateway Trailhead two miles out for a $10 day-use fee, no reservation required.
Are dogs allowed on the Blue Lake trail?
Yes, on a hand-held leash. From May 1 through November 14, dogs must be leashed at all times in the recreation area and on the trail, which lies inside the Indian Peaks Wilderness. From November 15 through April 30, dogs are restricted to the Brainard Lake and Lefthand Park Reservoir roads.
When is the best time to hike Blue Lake, and will there be snow?
Mid-July through September is the sweet spot, after the upper trailheads open and the snow melts out of the cirque. This is high country below the Continental Divide, so snow lingers late, the trail can be hard to follow under snow cover, and ice can rim the lake into early summer. Start early to beat afternoon thunderstorms.
Sources
Facts on this page are drawn from these authoritative sources: