The Michigan Department of Natural Resources (DNR) wants Upper Peninsula residents who spot black bear dens to pick up the phone.

An estimated 11,040 black bears live in the U.P. The agency is asking hikers, hunters and anyone spending time in the woods to report den locations during the fall and winter denning season, according to a DNR news release published by the Soo Leader.

Michigan is home to an estimated 12,862 black bears total. Of those, 11,040 live in the Upper Peninsula and 1,822 in the northern Lower Peninsula, the DNR said.

Bears enter dens in October and November, the agency said. Dens can be hard to spot.

They may look like brush piles covered in snow or excavated holes in the ground, often near dense vegetation, rock crevices or fallen trees. Dens may have an icy opening that vents fresh air.

Anyone who thinks they've found a den should keep a safe distance and avoid disturbing the site or the bears inside. The DNR advises listening quietly for sounds of cubs nursing or crying. Record the location with GPS coordinates if possible, then report it to DNR staffer Cody Norton at 906-202-3023 or [email protected].

Norton, the DNR’s bear, furbearer and small game specialist, said in a September WLUC report on the opening of bear hunting season, “Hunters provide our primary tool for estimating bear abundance and monitoring what’s going on with the bear population.”

The DNR said public den reports support its bear management programs.

After receiving a den report, DNR biologists determine whether the bear is a good candidate for the department's ongoing research project, the release said. A selected bear is sedated and fitted with a collar and ear tags.

Biologists collect the animal's sex, weight, body measurements and reproductive history. They also remove a small, nonfunctional tooth to get a DNA sample and determine age. The bear is then returned to its den for the winter.

Disturbing a bear den or a bear inside one is illegal under the DNR’s bear regulations. The agency also warns that it is dangerous. Anyone who finds a den should report it and let biologists investigate.

For dens found in the northern Lower Peninsula, residents can contact Mark Boersen at 989-275-5151, ext. 2722730, or [email protected]. More information is available on the DNR’s bear management page.