Olympic Hot Springs in Olympic National Park is a cluster of 21 thermal seeps near Boulder Creek, with water temperatures ranging from tepid to 138°F. The Klallam Tribe used the springs for centuries for vision quests. Andrew Jacobsen, aided by a Klallam friend, became the first known person of European descent to reach them in 1892, and after their rediscovery in 1907 a trail and resort were established. The resort lasted until 1966, after which the site returned to a more primitive state. Fed by groundwater heated underground along a fault, the shallow pools are now reached by a much longer hike and remain rustic and unmaintained.