MILLINOCKET, Maine — Gary Rideout knew that something was raiding his Dumpster and he saw exactly what it was as he was closing his neighborhood supermarket sometime last week, he said Monday.

It was after 10 p.m. Rideout was about to leave his Rideout’s Market when he saw a fairly large black bear on Poplar Street. He wasn’t afraid of it, he said.

“I was inside,” Rideout said.

Rideout suspects that the black bear, which ran up the street away from him, was the largest of three black bears that have been seen in several neighborhoods over the last few weeks.

One of the three reportedly was captured on a surveillance camera at Millinocket Regional Hospital as it came very close to the building’s entrance.

Hospital workers claim it triggered the motion sensor on the front doors with its big hairy head and ran away when the doors started to open. Hospital officials could not be reached Monday, despite a visit to MRH and messages left with CEO Marie Vienneau.

Rideout and residents interviewed Monday said the two smaller bears appeared to weigh about 100 pounds apiece while the largest looked closer to 300 pounds.

Bear sightings have been reported in Millinocket on several roads, including Bates, Poplar and School streets and Katahdin Avenue. The bears seem to be hunting for food in garbage cans, Dumpsters and back yards.

Appearances of such animals in residential areas of Millinocket, a northern Penobscot County town surrounded by thick woods near Baxter State Park, are not unusual, Town Manager Eugene Conlogue said.

“This happens every four or five years because of the food supply,” Police Chief Donald Bolduc said. “All we can do is ask people to bring in their bird feeders, garbage cans and barbecue grills because the bears love that stuff.”

Bolduc speculated that bears were foraging in town for food because of an early spring and a late berry bloom caused by the unusually wet weather. Maine Department of Inland Fisheries and Wildlife officials, however, have said that bear food is plentiful in the woods.

Bear sightings have climbed dramatically this year. Between Jan. 1 and July 3, the Maine Warden Service received 542 bear-related complaints, compared with 292 in the same period of 2010 and 252 in 2011, DIF&W officials have said. Bear sightings have been reported in many places, including Presque Isle and many towns in New Hampshire.

Bolduc, who said he has seen pictures and videos of the bears taken by residents, advised everyone to stay away from them.

“They are more afraid of us than we are of them,” he said.