Collinsville is an unincorporated rural community in Solano County, California, USA. It is located next to the Sacramento River Delta on the north side of the Sacramento River, and is effectively separated from the more intense urban development in Contra Costa County immediately across the river. The area was once proposed for a major chemical plant of the Dow Chemical Company in the 1980s. The community is in ZIP code 94585 and area code 707.
Collinsville was part of the Montezuma Township when purchased by C. J. Collins around 1859. S. C. Bradshaw later purchased the land and renamed it Newport. He tried to sell pieces of the land to people on the East Coast telling them that it was going to be a big railroad town. The land was later sold to E. I. Upham who returned the name Collinsville back to the town.
At one point, one of the passenger railroad lines between Sacramento and San Francisco passed through Collinsville (before the bridges were built). The train would unbuckle at Collinsville, and be pulled across the Delta by barge (requiring several trips), and then be rebuckled together on the other side, and resume its trip to San Francisco.
In the state legislature, Collinsville is in the 2nd Senate District, represented by Democrat Noreen Evans, and in the 8th Assembly District, represented by Democrat Mariko Yamada.
Federally, Collinsville is in California's 3rd congressional district, represented by Democrat John Garamendi.
Coordinates: 38°04′37″N 121°50′56″W / 38.07694°N 121.84889°W