habitat quality. Since steelhead in the Bay Area and California's Central Coast were listed as threatened under the Endangered Species Act in 1997, numerous organizations, including the Alameda Creek Alliance, and governmental agencies have cooperated on restoration projects to allow migratory fish from the Bay to reach spawning habitat in upper Alameda Creek, beginning in 1999. Alameda Creek is considered a potential ‘anchor watershed’ for steelhead, regionally significant for restoration of the threatened trout to the entire Bay Area, although by the late 1950s the California Department of Fish and Game decided the steelhead run was no longer viable due to numerous man-made barriers to fish runs. By the early 1970s the Army Corps of Engineers channeled and rip-rapped the lower of the creek. The last steelhead and coho salmon runs were seen in the lower creek in 1964, the latter confirmed by photographic records. Recent physical evidence has proved that the southern limit of coastal Chinook salmon included the southernmost tributaries of South San Francisco Bay. In 2009, the Alameda County Water District removed a rubber dam that blocked trout passage in the lower creek, adjacent to Quarry Lakes Regional Park. In June, 2010 environmentalists and water district officials celebrated the removal of a dam on Alameda Creek in Fremont, and the planned installation of fish ladders to allow salmonids to bypass two other dams on the lower creek. At the same time, PG&E is working to modify a cement barrier farther upstream in Sunol to help steelhead swim farther into the watershed, water officials said. Ground was broken on the first ladder the Alameda County Water District is building in April 2018 and is just west of the Mission Boulevard overcrossing in the Niles district of Fremont, allowing passage around a rubber dam. The second ladder, which should start construction in 2019, is about a mile downstream at the concrete structure, called a weir. The two ladders are funded by nearly $10 million in grants from several agencies, including $5.36 million from the California Wildlife Conservation Board and $3 million from the California Natural Resources Agency. When those projects are completed in 2021, steelhead will be able to migrate upstream to spawning habitats in the Sunol Valley for the first time in a half-century. California's archaeological record has contributed to knowledge of the prehistoric distribution of fishes in Alameda Creek and its tributaries including Sacramento perch (Archoplites interruptus),