On November 4, 2004, the National Park Service approved a Finding of No Significant Impact (FONSI) (345KB pdf) for the Temporary Winter Use Plans and Environmental Assessment (1.1MB pdf) for Winter Use in Yellowstone and Grand Teton National Parks and the John D. Rockefeller, Jr., Memorial Parkway. The Final Rule (356KB pdf) implementing this decision was published in the Federal Register on November 10, 2004.

This decision allowed 720 snowmobiles per day in Yellowstone, all commercially guided. In Grand Teton National Park and the John D. Rockefeller, Jr., Memorial Parkway, 140 snowmobiles were allowed daily. With minor exceptions, all snowmobiles were required to meet NPS best available technology (BAT) requirements. The plan was in effect for three winters, allowing snowmobile and snowcoach use through the winter of 2006-2007. Preparation of this plan allowed the NPS to complete a long-term analysis of the environmental impacts of winter use in the parks. The NPS expects that this long-term analysis will culminate with a permanent decision about winter use in the parks in fall 2007.

The temporary winter use management plan ensured that resources were protected, gave visitors, employees and residents of the park’s gateway communities the information they needed to plan for the near term, and helped minimize economic impacts on gateway communities. It also allowed the NPS to use new information derived from monitoring park resources during the winters of 2003-2004 through 2005-2006 in analyzing the impacts of the plan’s alternatives.

The EA did not address the issue of whether or not groomed roads influence bison distribution and abundance in Yellowstone National Park. The NPS contracted with an independent researcher to produce a thorough scientific assessment of the state of knowledge of bison use of groomed oversnow roads within Yellowstone. This study became available in April 2005. The report assessed the existing literature on bison movements and dispersal in Yellowstone, focusing on the ecology of bison movements in the park, including the influence of groomed and/or plowed roads. In addition, the report made recommendations concerning areas where additional research is needed, and investigated approaches that might be used to better understand use of groomed roads by bison. Some of these recommendations were utilized in the analysis for the current long-term analysis.