After California became a U.S. state, the California Gold Rush drew some prospectors to the Kaweah in the 1850s, but not much gold mining occurred in the area. During this time, the Kaweah was often known as the "River Francis", a corruption of the old Spanish name. Hale Tharp, a stockman and early settler in Three Rivers, discovered the Giant Forest in 1858 with the help of Native American guides. In 1861 Tharp returned to this area between the Middle and Marble forks of the Kaweah River, using a hollowed-out fallen sequoia log (Tharp's Log) as a cabin. In 1873, a silver boom in Mineral King attracted thousands of people to the high mountain valley along the East Fork. The peak of mining had passed by 1882, when the Empire Mine (owned by state senator Thomas Fowler, who invested most of his fortune in the mine) went under. Small operations continued, sporadically, into the late 1920s. After the end of silver mining, Mineral King became a popular summer resort.