Hog Island is an island of roughly 2 acres (0.8 ha) in size located approximately 5 mi (8 km) south of the entrance to Tomales Bay in the West Marin area of Marin County, California.
The name Hog Island reportedly came from a bizarre 1870s incident when a barge carrying a load of pigs caught fire and was grounded on the island to avoid sinking, at which point the pigs escaped onto the island until they were rounded up again.
The San Andreas fault runs through the center of Tomales Bay, past Hog Island. Local legend has it that Hog Island and nearby Duck Island (also known as "Piglet") were once connected, but separated as a result of the 1906 San Francisco earthquake. Despite the legend, land deeds from the 1880s indicate that the two islands were separate before the earthquake. The two islands have been intermittently linked by a sand spit exposed at low tide, including at the current time.
The Inverness Yacht Club hosts an annual sailboat race around the island. Competing boats sail from the club, around the island, and back to the club again.
Accessible by boat only