Marshall is an unincorporated community in Marin County, California. It is located on the northeast shore of Tomales Bay 6 mi (9.7 km) south of Tomales, at an elevation of 25 ft (7.6 m).

The North Pacific Coast Railroad (NPC) was a common carrier 3 ft (914 mm) narrow-gauge steam railroad begun in 1874 and sold in 1902 to new owners who renamed it the North Shore Railroad (California) (NSR) and which rebuilt the southern section into a standard-gauge electric railway.