Fork of the San Gabriel River, closing Crystal Lake Recreation Area for several years. The 2009 Station Fire, the largest wildfire in Los Angeles County's history, was mostly concentrated west of the San Gabriel watershed, but did burn much of the upper West Fork. With urban development expanding toward mountain areas, the threat of property damage continues to increase. The San Gabriel River historically supported large populations of native fish, including the largest runs of steelhead in Southern California. Steelhead once migrated over upriver from the Pacific Ocean to spawn, and it was known as one of the "best steelhead fishing rivers in the state". Irrigation development that dried up the river, and later damming and channelization for flood control, have contributed to the near extinction of steelhead in the San Gabriel basin. Since the 19th century rainbow trout have been planted in the upper forks of the San Gabriel River to provide a recreational fishery. About 60,000 rainbows are stocked each year between October and June. The West Fork also has the largest remaining population of arroyo chub, a fish endemic to coastal Southern California streams. Human history Native Americans Although the first recorded inhabitants of the San Gabriel River area arrived about 2,500 years ago, humans may have been present in Southern California as early as 12,000 years ago. Immediately prior to the arrival of Spanish explorers in the region the native population is estimated at 5,000–10,000. Mount San Antonio provided a visual reference for the boundary of the Tongva (Gabrielino) people in the west and the Yuhaviatam people to the east. Most of the San Gabriel River lay in traditional Tongva territory, although the Chumash (who inhabited areas further west) also used the area. Tongva villages such as Puvunga were located on high ground above the reach of winter floods. A typical village consisted of large, circular thatched huts known as "kich" or "kish", each home to multiple families. During summer the villagers would travel up the San Gabriel Canyon into the mountains to gather food and other resources needed to pass the winter. The San Gabriel River itself also provided sustenance to Native Americans with its steelhead trout and game animals attracted by this rare permanent water source. The abundant plant life around the river and its marshes, especially tule, were used to build dwellings and canoes. The Tongva often set brush fires to clear out