In the fall of 2021, a grizzly bear dubbed Lingenpolter by Montana wildlife officials wandered south until he bumped into the traffic on Interstate 90.

Young male bears, known as boars, tend to roam, and Lingenpolter, tracked by a GPS collar, bounced around the highways perimeter repeatedly until settling into hibernation. After emerging in the spring, he returned to the task and finally, after at least 46 attempts , he crossed the road.

The breakthrough made Lingenpolter one of several grizzlies in recent years to bust his way past the formidable obstacles blocking bears from traveling toward the Bitterroot ecosystem, a region that stretches across northern Idaho and a small swath of western Montana.

Grizzly conservationists have long viewed the region as a key area for recovering the keystone species, whose range in the contiguous United States has been reduced to a handful of recovery zones since being listed as threatened in the Lower 48 under the Endangered Species Act. But for two decades, the federal government took no action to urge restoration to the Bitterroot, even though the mission to return bears there is written into federal law.

That hands-off policy is quickly changing now that grizzlies are wandering back into the area on their own.