The Challenge
The National Park Service needed noise and soundscape analyses for environmental impact studies of snowmobile and snow coach use on the groomed roads at Yellowstone and Grand Teton National Parks.
The Strategy
HMMH:
- Measured reference noise levels of many snowmobile and snow coach pass-bys
- Monitored wintertime noise levels
- Modeled park-wide noise levels and vehicle audibility for alternative use scenarios
- Computed how far away from a trail a snow machine is audible(after measuring natural background noise)
- Calculated the acres of park affected by the noise
The Solution
The Park Service has used our measurements and analyses, the first of their kind in the U.S, to establish policies for wintertime motorized vehicle use.



