Stage 4 of the John Muir Trail covers 15.6 km from Upper Lyell Canyon to Thousand Island Lake, with 828 m of ascent and 476 m of descent. The highest point is 3,376 m. Allow about 5.5 hours of walking, plus breaks.
Distance, climb and elevation come from the Outest route data. Difficulty and time are estimates from distance and climb; your pace will vary with heat, pack weight and photo stops.
Large lake in the Ansel Adams Wilderness at about 3,000 m (9,830 ft) below Banner Peak. No camping within 1/4 mile of the outlet, no campfires in the Thousand Island Lake area, and bear canisters are required on this part of the JMT.
Checked online in October 2026. Places marked "not confirmed on an official page" are listed elsewhere but could not be checked on their own or an agency website. Your wilderness permit lets you camp where it is legal, at least 100 ft (30 m) from water and the trail; some lakes have extra limits. Bear canisters are required.
Emergency: call or text 911 (no signal on most of the trail). Emergency & health guide
Pharmacies, ATMs, shops and stops: © OpenStreetMap contributors. Hospitals and health centres checked online.
The full stage works offline in Outest, with the route, elevation, water and village points, and a trail guide you can ask about conditions and the next place to sleep.