Earlier this month, two mushroom experts from the East Bay stumbled across a treasure of a different kind in Tomales Bay State Park: Fresh bear poop. Debbie Viess and David Rust, who together founded the Bay Area Mycological Society, found the scat after pulling over on Pierce Point Road. “We were groking the bay when we noticed a little something right where we had parked our car,” Mr. Rust said. The couple said they saw a similar specimen on a recent trip to Colorado and have encountered bears while foraging in Yosemite and Alaska. They identified the culprit right away, and believed the scat looked about a day old. They took a photograph and brought it to the Bear Valley Visitor Center. After he was shown the photograph this week, local tracker Richard Vacha said it definitely came from a black bear. “I’d call it a young dispersal male, for a first guess,” he speculated. “A grown-up yearling, probably not this season’s young.” The last bear in the area was seen in 2010, and before that in 2003, park spokesman John Dell’Osso said. No other evidence of a bear in the area has turned up this time, but the park may have the scat tested to be sure of the species, he said. While there were likely as many as two million black bears in North America at one time, the population has declined to a low of 200,000 as a result of habitat degradation and hunting, according to the park service. Black bears had a historical presence in the Point Reyes area, but went extinct in 1901. Before the 2003 sighting, there was an unconfirmed sighting in 1971 near Hagmaier Ranch. Male black bears are between five and six feet long, two to three feet tall and weigh between 300 and 350 pounds; females can weigh up to 250 pounds. Mr. Vacha had a theory as to how they arrive at the western side of Tomales Bay: “I think they come down from the Russian River and swim the bay to get into the pine forests. They like the Myrtle berries, which are ripening now.”