Grassy Swale Loop

Grassy Swale Loop is a 13.4-mile day loop from the Summit Lake area, down toward Corral Meadow and Kings Creek, then north through Grassy Swale and the Swan and Twin Lakes, returning by Echo Lake. The mapped route gains about 1,450 feet and stays high, roughly 6,000 to 7,200 feet. It is a long, varied circuit for hikers who want meadows, creek crossings and several lakes in one demanding day.

Allow about nine hours, with extra time for the two Kings Creek fords and lake stops. This is hard hiking because of the distance, altitude, uneven trail and water crossings, even though the total climb is moderate. The route description favors mid-August through October; snow can linger into summer, mosquitoes are common in July, and creek levels may stay high into August. Check current trail and water conditions before you go.

The loop uses the Summit Lake to Corral Meadow trail, crosses Kings Creek, follows the Pacific Crest Trail through the namesake swale, then links Swan and Twin Lakes to Echo Lake for the return. Short boardwalk sections cross the wet swale. Some junctions and connectors are faint or only partly represented in trail data, so carry a detailed map and know the next lake or junction before leaving each one. A shorter, roughly 11.6-mile loop has also been described from this same area; this entry follows the longer 13.4-mile mapped circuit.

There are two unbridged Kings Creek fords. One is described as especially difficult when water is high; do not enter moving water you cannot safely cross, and be ready to turn back. Fire-affected sections also have standing dead trees that can fall without warning. The stored route is an older mapped alignment checked against current path geometry, so verify the latest park conditions and route access before starting.

Grassy Swale is a green, wet meadow corridor between drier ridges, with boardwalk through its soggier ground. Swan and Twin Lakes add shoreline stops; Echo Lake marks the return leg. Start at Summit Lake Ranger Station/Trailhead and use the developed Summit Lake access. The older route map does not fix the exact parking junction, so confirm the starting connection on a current park map. Pets are prohibited on hiking trails. If extending this day hike into an overnight backcountry trip, obtain the required wilderness permit and carry the required bear-resistant food canister.