Long Lake is accessible from the Long Lake Trailhead in the Brainard Lake Recreation Area of the Indian Peaks Wilderness. It fills a large, level basin fed by South St Vrain Creek, whose origin lies with Isabelle Glacier 4.35 miles west along the Continental Divide.

The Pawnee Pass Trail joins the Jean Lunning Trail to form a diverting loop around Long Lake. This short, versatile trail is well-suited for families, trail running, and winter activities. Visitors will enjoy lengthy stretches of accessible shoreline, scenic inlet and outlet streams, excellent fishing, abundant wildflowers, and good views of the upper valley and Niwot Ridge.

The following description travels counter-clockwise from the Long Lake Trailhead:

A level path follows Long Lake's outlet stream to the first of two connections with the Jean Lunning Trail (.2 miles : 10,524'). It levels through mature spruce past the lake's west shore to the second Jean Lunning Trail connection (1.2 miles : 10,674') - turn left.

The trail bends south and drops to a bridge over Long Lake's primary inlet (1.35 miles : 10,636'). It rises back and curls around a marshy basin to the lake's stream-crossed southwest corner (1.95 miles : 10,584'). The lake's south shore is damp and open - ideal conditions for wildflowers. The trail glides easily through flower-dotted meadows to the southeast corner and turns north over the outlet stream (2.5 miles : 10,550').

From this central location in the valley you'll enjoy sweeping views across the lake, Niwot Ridge and Navajo (13,409'), Apache (13,441') and Shoshoni (12,967') peaks. The trail rejoins the Pawnee Pass Trail (2.6 miles) and returns to the Long Lake Trailhead (2.8 miles : 10,515').