Rare San Francisco river otter stumps researchers

SAN FRANCISCO - For the first time in decades, a river otter has made San Francisco its home, taking up residence in the ruins of a 19th Century seaside bath near the Golden Gate Bridge.

The otter has mystified and delighted conservationists, who are piecing together clues to figure out how he got there.

River otters once thrived in the San Francisco Bay area. But development and the fur trade in the 19th and early 20th centuries nearly wiped them out.

A group called the River Otter Ecology Project studies otter populations further north and in the bay. It says until now it had no evidence the creatures had returned to San Francisco.

The otter is nicknamed "Sutro Sam" after the old baths, which were named after former San Francisco Mayor Adolph Sutro.