Pawnee Pass

Pawnee Pass at a glance

Pawnee Pass is the big one. Where Long Lake and Lake Isabelle are gentle walks below the Continental Divide, Pawnee Pass climbs right over it. The Pawnee Pass Trail leaves the Long Lake Trailhead inside Brainard Lake Recreation Area, follows the valley past Long Lake and up to Lake Isabelle, then grinds up a steep headwall of switchbacks to a saddle on the Divide at about 12,540 feet. It's a serious, all-day alpine hike in the Indian Peaks Wilderness, with long stretches above treeline and no shade near the top. The reward is a Divide crossing with views west into the wilderness and, for those who continue, a link into the classic Pawnee-Buchanan loop.

The route: Long Lake to Lake Isabelle to the pass

The trail starts easy. From the Long Lake Trailhead it runs nearly level along Long Lake, then climbs gradually through subalpine forest and meadow to Lake Isabelle, sitting in a bowl right beneath the Divide. That's where the character changes. Above Lake Isabelle the trail breaks out of the trees and switchbacks up the headwall to the pass, gaining most of the day's elevation in the upper half. The Forest Service doesn't publish an official distance, but trail-mapping sources put the full round trip at roughly 9 to 10 miles with about 2,000 to 2,500 feet of climbing. Lake Isabelle makes a natural turnaround if you want a shorter, easier day.

How strenuous is it, really

Strenuous, and honestly so. The distance alone makes it a long day, but the altitude is what defines it: you finish above 12,500 feet, higher than most Boulder foothill summits, on thin air and exposed terrain. The upper switchbacks are steep, the wind on the Divide can be fierce even in July, and there's no shelter up high. Come acclimated, carry more water and layers than you think you need, and be honest with yourself about turning around. Strong hikers with an early start do this as a day hike; it is not a trail to underestimate.

Start early: afternoon storms and lightning

This is the single most important rule on Pawnee Pass. In the Colorado high country, thunderstorms build over the Divide most summer afternoons, and the upper half of this trail is fully exposed above treeline, exactly where you do not want to be caught in lightning. Plan to be off the pass and heading down by noon or early afternoon, which means starting at or before dawn. Watch the sky the whole way up, and if clouds are stacking up over the Divide, turn around, the pass will still be there another day. Our thunderstorm-safety guide walks through the timing and the warning signs.

Reservations, access, and fees

The Long Lake Trailhead is an upper trailhead inside Brainard Lake Recreation Area, so during the operating season you need a timed-entry parking reservation from Recreation.gov to park there. The upper lots don't open until the snow melts in July. The reservation runs $16 per personal vehicle plus a $2 reservation fee; an America the Beautiful, senior, or access pass drops it to just the $2 fee, though you still have to book. If you'd rather not deal with a reservation, you can park at the year-round Gateway Trailhead and walk or bike in for a $10 day-use fee, but that adds real miles to an already long day. Our Brainard Lake guide covers the whole timed-entry system in detail.

Wilderness rules and dogs

The whole route is inside the Indian Peaks Wilderness, so the wilderness rules apply from the trailhead. You don't need a permit for a small-group day hike, but overnight camping requires a backcountry permit from June 1 through September 15, large groups of 8 to 12 need a day-use permit in that window, and bear canisters are required year-round near the trailheads. Group size is capped at 12, and bikes and other mechanized travel are not allowed on wilderness trails. Dogs are welcome but must be on a hand-held leash at all times, the voice-and-sight approach from Boulder's foothill trails does not apply here.

Beyond the pass: the Pawnee-Buchanan loop

For most day hikers, the pass is the destination and the turnaround. But Pawnee Pass is also the eastern gateway to one of Colorado's classic backpacking routes: from the pass, the Cascade Creek Trail drops west down the far side of the Divide, and the full Pawnee-Buchanan loop links it with Buchanan Pass for a big multi-day circuit through the heart of the Indian Peaks. If you're eyeing that trip, plan for permits, weather, and real backcountry experience, it's a serious undertaking well beyond a day hike.

Best time to go

Aim for mid-July through September. Snow lingers on the pass and the upper switchbacks into July most years, and the upper trailhead lots don't open until the snowmelt anyway, so earlier than mid-July you're often parking low and post-holing high. The snow-free window above treeline is short. Whenever you go, start before dawn to beat the afternoon storms, carry layers for cold Divide wind, and check conditions before you commit to the full pass.

Nearby trails and guides

• Lake Isabelle: the alpine lake below the Divide that makes a natural turnaround, or a shorter, easier hike on its own.
• Brainard Lake Recreation Area: the full guide to the timed-entry reservations, fees, road season, and every trailhead.
• Thunderstorm safety: how to time an above-treeline hike so you're down before the afternoon storms.
• All hikes in Boulder: the full hiking hub, sorted by difficulty.

Recommended nearby

A few local spots we'd point a Pawnee Pass day toward.

Pawnee Pass FAQ

Sources

Facts on this page are drawn from these authoritative sources:

• US Forest Service: Brainard Lake Recreation Area (Arapaho and Roosevelt National Forests)
• US Forest Service: Indian Peaks Wilderness (rules, permits, pets)
• Recreation.gov: Brainard Lake Recreation Area Timed Tickets
• Wikipedia / USGS GNIS: Pawnee Pass elevation and coordinates