SAN FRANCISCO (CBS/AP) — Earlier this year, a river otter named Sutro Sam became the first of the whiskered critters to be seen in San Francisco for decades.

Then, in October, a rower on Oakland’s Lake Merritt photographed a river otter hoisting itself onto a dock. Earlier this month, a man walking along Richmond Marina was surprised to see another otter.

In all, researchers have received 600 reported sightings throughout the San Francisco Bay region over the past two years in the first population study of the weasel-like creatures ever done here.

Most of the sightings have been in an area where the species was nearly wiped out after decades of hunting and development.

While scientists say it’s too early to claim victory, many are encouraged by the otters’ apparent bounce back.

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