The thicktail chub (Gila crassicauda) was a type of minnow that inhabited the lowlands and weedy backwaters of the Sacramento and San Joaquin Rivers in the Central Valley of California.

It was once abundant in lowland lakes, marshes, ponds, slow-moving stretches of river,[2] and, during years of heavy run-off, the surface waters of San Francisco Bay.

[3] The chub was a favored food of the indigenous peoples of Clear Lake and the Central Valley before being heavily exploited by commercial fishermen supplying the San Francisco market.

[2] A heavy-bodied fish with a thick tail and a small, cone-shaped head, the backs of the thicktail chub ranged in color from greenish brown to purplish black, while the sides and belly were yellow.

Most of its habitat was destroyed by the drainage of sloughs and marshes, dam-building, and water diversion for irrigation.