A technical document, part of the current draft environmental impact statement on Yellowstone snowmobile use tells that the requirement that snowmobilers have guides has reduced, but not eliminated, the stress snowmobiles create on the wintering wildlife.
Bald Eagles are the species that show the most stress, followed by elk and coyotes. While the grooming of roads affects bison, especially those bison deep the in the Park, the bison was the animal that showed the lowest stress response of those studied.
Story in the Jackson Hole News and Guide. By Corey Hatch.
