The female black bruin known only as Bear No. 56 was 39 1/2 years old. Her decomposed carcass was discovered Aug. 21 in the Chippewa National Forest, the Minneapolis Star Tribune reported Tuesday.
Karen Noyce, a researcher for the Minnesota Department of Natural Resources, discovered the bear's remains in the woods near Marcell.
"We're very fond of that bear," Noyce told the newspaper Tuesday. "But it's not like a pet or anything, when you have a relationship."
No. 56 had first been captured and had a radio collar placed around her neck in July 1981 when she was 7. She had three female cubs at the time.
No. 56 produced eight litters of cubs and successfully reared 21 of the 22 cubs to 18 months of age from 1981-95.
The DNR said the information gathered from No. 56 and her offspring has "contributed significantly to the scientific literature on black bear biology."
Noyce said she had spent time around the bear in recent years.
"I would sit there for a while, sit there and absorb sitting next to a very, very old bear," she said.
"She was having trouble getting around, but eating normally. She couldn't see and couldn't hear. She was stumbling around.
"We're glad to see she died a natural death. ... It was a good way to go."