Park biologists will be radio-collaring grizzly bears this fall as part of a project to assess impacts of Park Road traffic on the animals.
The Pretty Rocks landslide is halfway along the park’s 92-mile road. The exposed, multicolored slope had been slipping down slowly over time, but accelerated warming caused big movements and the road bed became dangerous. The park closed the road at Pretty Rocks in August, 2021.
Since that time, only hikers and bicyclists have accessed the western 50 miles of the road.
“The west end of the park road right now is getting no traffic at all.”
That’s Pat Owen, a park wildlife biologist. She wants to know if bears and other animals are changing their behavior without cars and the big busses of tourists.
“What we're trying to do is to collar some bears, to look at their movements and behavior, what they're doing out there in the absence of traffic.”
This fall, park staff will be catching grizzly bears and putting radio collars on them, before they go into hibernation. While that’s going on, the Park Road and adjacent backcountry units on each side of the road will be closed from the Teklanika river to about Wonder Lake. Owen doesn’t want any backcountry users to be surprised: No pedestrians, bicyclists, or backpackers will be allowed in the closed area while wildlife biologists are looking for bears from helicopters.
“Fingers crossed; the weather will be with us. If we get a little snow, so much the better - it makes it easier to see bears.
Owen says they were able to collar some bears in June that were in the closed area. And already their behavior is notable.
“All the bears that we've collared so far, bears initially that were near the road corridor, most of them are staying fairly close to the road. It's been pretty interesting to see there are clumps of locations that are not all that far from where we initially caught those bears.”
The National Park Service has contracted to build a suspension bridge over the unstable Pretty Rocks landslide that will allow tour buses to get to the western part of the park.
Owen says the data in this fall’s collaring study will build a base for that future.
“The plan is to keep these same bears radio collared once the road opens to see how they respond.”
The closing, and planned re-opening of the road provide a unique opportunity to study the before and after on the bears. She anticipates finding there is an effect once traffic resumes.
“Are their home ranges going to move away from the road? That's sort of what we would typically speculate because we assume that traffic is a disturbance, but you know this will show us if that’s really the case.”
The bridge is scheduled to be complete and the road re-opened in 2026.
