Doubtful Lake Trail

Doubtful Lake Trail is a 9.7-mile out-and-back from Cascade Pass Trailhead, over Cascade Pass and up Sahale Arm before a steep half-mile drop to the lake. Allow about seven to eight hours and expect roughly 3,000 feet of total climbing. This is a hard day for hikers comfortable with sustained uphill walking and a steep return climb. The payoff is a dark alpine lake, a small island and a high cirque below Sahale Mountain. If you want the pass without the extra climb and descent, Cascade Pass alone is about 7.4 miles round trip.

The first two miles climb through cool forest on switchbacks. Around mile three, the trees give way to meadows and the grade eases toward Cascade Pass, 3.7 miles from the trailhead. The pass opens views toward Eldorado, Johannesburg, Magic, Mixup and McGregor. Indigenous travelers used this crossing through the Cascades; fur trader Alexander Ross passed through in 1811, followed later by prospectors.

From the pass, take Sahale Arm north. The path climbs steeply through subalpine meadow and talus. About three-quarters of a mile later, it crests a rounded shoulder near 6,000 feet, where Sahale Mountain and its glacier come into view. The glacier sends bright meltwater ribbons down the slope toward the lake. The lake is hidden at first, then appears in peeks from the arm. Glacier lilies follow the snowmelt in early summer; mountain blueberries color the meadows in fall, and marmots are often about.

The lake spur leaves the arm about 0.8 mile beyond Cascade Pass, then drops roughly 700 feet in about half a mile to the shore. That short stretch is the steepest part of the day, and you'll climb it again on the way back. At the water, look for the little island below the gray cirque. The spur is less well described than the main pass trail, so be conservative if snow or poor visibility makes the line hard to read.

Cascade River Road runs 23.1 miles from Marblemount to the trailhead; its first third is paved, then it becomes gravel, with narrow and steep sections near the end. The road usually opens by late June, or early July in heavy-snow years. The shared trailhead can be busy on summer weekends. Pets aren't allowed. Overnight stays require a backcountry permit and camping is limited to designated sites; there is no camping at Cascade Pass or Doubtful Lake. Snow can linger on steep sections into July, when an ice axe may be needed.