The Petaluma and Santa Rosa Railroad was an electrified interurban line of approximately 32 miles of track beginning about 30 miles north of the north end of the Golden Gate Bridge. A merger of four horse car rail line companies in 1903 created the railroad which ran until being purchased 1932. Besides the movement between the local cities, it connected at the south to a railroad owned ferry to take folks to San Francisco. The Golden Gate Bridge construction began only a few months after the railroad was bought out.
The Western Pacific RR also formed in 1903 and was purchased by Union Pacific RR in 1982. It ran, with two other railroads several famous passenger trains including the Exposition Flyer with with service from Chicago to the 1939-40 Golden Gate International Exposition on Treasure Island in the San Francisco Bay. It was temporary in plan but ran to 1949 when replaced by the California Zephyr, a world famous train due to the scenic route it traversed. Unlike the Petaluma and Santa Rosa Railroad, WP mainline trackage is still in use by UPRR.