River otters had not been known on California’s San Mateo coast since the 1800s

Some of the wildlife’s most exciting discoveries happen when you accidentally find one thing in search of another. NBC Bay Area News has reported that wildlife cameras installed to observe foxes on California's San Mateo coast ended up capturing an animal that researchers had not expected to find in the area at all.

A North American river otter appeared on camera at the Cloverdale Ranch Open Space Preserve near Pescadero, with photographs taken across a period of three months in the summer of 2026. Conservationists are thrilled by the sighting, given that this species had not been documented on the San Mateo coast since the 1800s.Ken Hickman, an independent researcher who first noted the discovery, works with the Midpeninsula Regional Open Space District, which manages the preserve.

While reviewing the camera images, Hickman spotted the otter and shared the photographs with biologists, who confirmed the animal's identity.