Adithya Sambamurthy/The Bay Citizen

Red Rock Island as seen from the San Rafael Bridge in Marin County on Tuesday, May 10, 2011. The uninhabited island is privately owned

Jutting out of the blue near the Richmond-San Rafael Bridge is Red Rock Island, a homely atoll with a colorful history and a sizable price tag. Many have made plans over the years to develop this ideally situated islet with spectacular views, but it is currently uninhabited.

WHAT’S THERE?

Scattered brush, a few pine trees, migrating Canada geese, sea gulls, bats and perhaps rabbits, and former mine tunnels. The island is 500 feet wide, 750 feet long and 176 feet high. Only a 20-minute ride from Sausalito, the beach provides safe landing for boaters and driftwood for campfires.

STONE VALUE

The “red rock” of the island is oxidized manganese. Tons of this low-grade ore were removed in the 1860s and shipped to Europe to be used as paint pigment. Perhaps more valuable than the manganese is the island’s Franciscan schist, a rock used in road building.

TRIPLE COUNTY

Red Rock Island encompasses three counties because it was established as a triangulation point by surveyors in 1850. About four acres of the island are in Contra Costa County, one and a half acres are in San Francisco County, and less than one-tenth of an acre is in Marin County.

FLIP IT

A San Franciscan, David Glickman, bought the island in 1964 for $49,500. Today it is on the market for $22 million, including mineral rights.

SAD SLAUGHTER

Russian and Aleutian fur hunters, looking for sea otters, used Red Rock Island as a campsite in 1812. Thousands of sea otters lived in San Francisco Bay until they were clubbed and trapped to near extinction.

POPULATION: 1

Selim Woodworth built a cabin and lived on Red Rock Island in the 1800s. He tried to claim title to the island via the Homestead Act, but officials refused because they thought the government would eventually use the area.

TINY SIBLINGS

Red Rock is the only privately owned island in San Francisco Bay, but at 5.783 acres it is far from the smallest. The Brother Islands and the Sisters, two pairs of nearby rocky islets, are all one acre or less in size.

CULT CUSTOMER

The island was almost sold in 1985 to Bhagwan Shree Rajneesh, the Indian “sex guru” with 93 Rolls-Royce limousines who set up a commune in Oregon. In 1984, his followers contaminated restaurant salad bars in Oregon with salmonella. The Red Rock deal fell through when Bhagwan was deported.