Hat Creek Headwaters is a point-to-point hike from the Hat Lake trailhead toward Summit Lake through Lassen Volcanic’s upper Hat Creek drainage. The connected mapped through-line is about 6.1 miles and takes roughly five hours on foot; allow more time for lake and meadow side trips. It is not a loop, so arrange a vehicle shuttle or pickup at the far end. The road connection between the trailheads is about 2.4 miles.
An older route map lists 7.3 miles and shows several lake and meadow visits as out-and-backs. Their added mileage is not fully traceable in current mapped paths, so this record follows the connected 6.1-mile line and treats those excursions as optional. The mapped line approaches the Summit Lake access area but does not connect exactly to the Ranger Station map pin; follow park signs for the final approach.