Snowmobiles will be permitted in Yellowstone and Grand Teton under the National Park Service’s final environmental impact statement, released yesterday. The park service acknowledges that the plan is not the best one in terms of improving air quality, reducing noise, or protecting the health of park workers, visitors, and wildlife. Under the plan, only “cleaner and quieter” snowmobiles will be allowed in the parks and riders will have to receive training or be accompanied by a guide. The plan will also cap the number of machines allowed in the parks at 1,100 per day (which is about how many enter, anyway) and distribute the total load over different entrances to reduce congestion. Park officials said the plan strikes a balance between today’s unlimited use and the Clinton proposal to phase out snowmobiles entirely, but former National Parks Service Director Roger Kennedy criticized the proposal for giving equal weight to snowmobile access and human and environmental health: “It says to the world we are striking a different balance, and commerce will supervene the health of the world.”