The lexicon built around enjoying the winter season in Yellowstone National Park grew this year when park officials coined "transportation events" to help define the impacts of snowmobiles and snowcoaches. But that phrase has even Environmental Protection Agency officials scratching their heads over exactly what it represents.
In working through a fifth environmental impact statement geared towards crafting a reasonable winter-use plan for the park, Yellowstone officials chose to "manage oversnow vehicles by their overall impacts to air quality, soundscapes, wildlife, and visitors, rather than focusing solely on the number of snowmobiles and snowcoaches allowed in the park each day."
To do so, park planners defined a "transportation event" as equaling one snowcoach or seven, (on average, or no more than 10), snowmobiles entering Yellowstone on a given winter say. Under the Draft Winter-Use Supplemental Environmental Impact Statement, up to 110 'transportation events' would be permitted a day.
In their comments on the plan, EPA officials questioned park officials on how they came up with their "transportaton events."
“The EPA was unable to determine how the NPS established thresholds for the maximum number of transportation events per day for the preferred alternative,” EPA officials wrote in a letter obtained by the Jackson Hole News & Guide. “Additionally, we could not ascertain the basis for establishing the maximum number of 10 snowmobiles per event.”
EPA officials also raised questions over why the park, in collecting emissions data from snowcoaches and snowmobiles, included a 2008 Chevy snowcoach when that model would not be allowed in the park's approved 2018 fleet. The Chevy's emissions, the EPA noted, "significantly increases" the overall emissions projections calculated by the park.
Yellowstone officials last week announced that they intended to extend a temporary winter-use plan for the coming winter season under which 318 snowmobiles and 78 snowcoaches would be allowed into the park on any day. They also said they would take additional public comment on the draft winter-use plan.