Yellowstone National Park Officials presented a revised proposal for the winter use plan and supplemental environmental impact statement during an open house in Jackson Monday evening. Four alternatives are under consideration ranging from one that would close off the park during the winter to public access, to a preferred alternative that would permit snowmobiles and snowcoaches into the park based upon their impacts on sound, air and wildlife interaction. Superintendent Dan Wenk says, the preferred alternative would also allow for increased numbers as technology evolves. Wenk says a final rule needs to be in place by December 15th in order for winter use to continue in Yellowstone. Then, Wenk says, the rule will be phased in over a number of years. Says Wenk, “Because of what we are requiring and we now know as the cycles when operators order their machines and when we have reservations to bring surety to the next two years; it has a two year phase-in period – and then some of the best technology as proposed would have additional 3 years phased in period. Comments on the SEIS are due by August.