Big Bear Lake is a popular resort city in California's San Bernardino Mountains, with a permanent population of about 5,046 that surges to over 100,000 on busy weekends. Inhabited by the Serrano people for millennia, the area boomed during the 1861–1912 gold rush, and while grizzly bears (its namesake) disappeared by 1908, black bears were introduced from Yosemite in 1933. After Kirk Phillips launched the world's second bus line to the valley, it became Southern California's first mountain recreation area, and by 1924 it had 44 resorts, including the Pan Hot Springs Hotel (1921), which attracted Hollywood legends like Cecil B. DeMille and Shirley Temple. A favorite filming location since the silent era (e.g., Last of the Mohicans and War Games), it also became a winter sports hub with the first ski jump in 1929 and the opening of Snow Summit in 1952. In 1968, Caltech established the Big Bear Solar Observatory on the lake's north shore.