The Marin Islands, clearly hidden in plain sight, may be the least known of San Francisco Bay’s scattering of islands.
By CaptaIn Ray
Published: April, 2012
The Marin Islands, clearly hidden in plain sight, may be the least known of San Francisco Bay’s scattering of islands. There are two of them, fittingly named East Marin and West Marin, and they are located about one and a half miles north of the western end of the Richmond/San Rafael Bridge.
Nautical charts give us very little information about these two small specks of land. The water surrounding them, called San Rafael Bay, is very shallow, generally one to two feet on the east side of the islands and four or five on the west. The chart shows a structure on East Marin Island, the larger of the two. You can see the islands as you drive across the Richmond/San Rafael Bridge; however, the closest shoreline view of them is from the breakwater protecting the Loch Lomond Marina.
These two islands and the surrounding submerged tidelands were designated the Marin Islands National Wildlife Refuge and State Ecological Reserve in 1992. The islands are the property of the United States Fish and Wildlife Service and special permission from the Service is required to visit them. The islands are mostly steep sided and covered with poison oak, so an unauthorized visit could be both difficult and unpleasant.
While the Refuge is small, about 350 acres, West Marin Island, which at 85 feet above sea level is the higher of the two, contains the largest egret and heron rookery in the San Francisco Bay area—and one of the largest in northern California. There are over 500 nesting pairs of great and snowy egrets, and great blue and black- crowned night herons. The shallow waters around the islands support a variety of resident and migratory fowl, including ospreys, black oystercatchers, surf scoters and diving ducks. Harbor seals also have been seen to haul out here.
Archaeological excavations conducted on East Marin Island have confirmed Native American presence on the islands. Radiocarbon dates of A.D. 210 and 720 suggest that the islands were visited for a long period of time. However, lack of human burials lead anthropologists to believe that the islands were visited only seasonally and there was never permanent human occupation.
In 1926, Thomas Crowley purchased the islands at auction for $25,000. He was speculating that they would be used in the construction of a bridge across San Pablo Strait, connecting Marin to Contra Costa counties. When a different route—one not utilizing the islands—was selected for the Richmond/San Rafael Bridge, they became a Crowley family vacation get-away spot for more than 60 years.
By the 1980s, plans were afoot for the development of the Marin Islands. During a period of more than 10 years, these plans were opposed by a variety of organizations and agencies, including the Friends of the Marin Islands, the California Coastal Conservancy, the Trust for Public Land, as well as the local citzenry and more than a dozen other organizations and agencies. In the summer of 1992, the Crowley family sold the islands to the State of California. Title was then transferred to the U.S. Fish and Wildlife Service and the refuge established.
The current management of the islands by the Service is focused on two areas: preventing human disturbance of the heron and egret rookery and monitoring the rookery with annual surveys. Future plans call for a system of buoys to warn boaters about the rookery and the removal of all nonnative vegetation and all structures.
Ray Wichmann, is a US SAILING-certified Ocean Passagemaking Instructor, a US SAILING Instructor Trainer, and a member of US SAILING’s National Faculty. He holds a 100-Ton Master’s License, was a charter skipper in Hawai’i for 15 years, and has sailed on both coasts of the United States, in Mexico, the Caribbean, and Greece. He is presently employed as the Master Instructor at OCSC Sailing in the Berkeley Marina.
