Snowmobiles and bison
The bison are more likely to make trouble for the snowmobilers than the other way around. The new 2-stroke machines are so much quieter and less polluting than the old 4-stroke machines, and the bison are so used to them that they will wander, often a whole herd at a time, into the road (groomed roads require far less energy expenditure for the bison in winter than slogging through deep snow) and just stay there. All over-snow vehicles must yield to them, which sometimes means a long wait.
Yellowstone's current requirements:
The “New BAT” designation refers to a snowmobile that meets the park’s Best Available Technology (BAT) standard. As of December 15th, 2015, all snowmobiles entering the park must operate at or below 67 dBA and must be certified to a Family Emission Limit (FEL) no greater than a total of 15 g/kW-hr for hydrocarbons and 90 g/kW-hr for carbon monoxide. A snowmobile will be certified for six consecutive winter seasons following its manufacture or until the snowmobile travels 6,000 miles, whichever occurs later. See the table below for a list of approved snowmobiles.
Lamar Valley, Yellowstone
Snowmobiles and bison
The bison are more likely to make trouble for the snowmobilers than the other way around. The new 2-stroke machines are so much quieter and less polluting than the old 4-stroke machines, and the bison are so used to them that they will wander, often a whole herd at a time, into the road (groomed roads require far less energy expenditure for the bison in winter than slogging through deep snow) and just stay there. All over-snow vehicles must yield to them, which sometimes means a long wait.
Yellowstone's current requirements:
The “New BAT” designation refers to a snowmobile that meets the park’s Best Available Technology (BAT) standard. As of December 15th, 2015, all snowmobiles entering the park must operate at or below 67 dBA and must be certified to a Family Emission Limit (FEL) no greater than a total of 15 g/kW-hr for hydrocarbons and 90 g/kW-hr for carbon monoxide. A snowmobile will be certified for six consecutive winter seasons following its manufacture or until the snowmobile travels 6,000 miles, whichever occurs later. See the table below for a list of approved snowmobiles.
Lamar Valley, Yellowstone