The Coalition of National Park Service Retirees and three other conservation groups have appealed to the federal government to close Yellowstone National Park's Sylvan Pass to winter visitors and discontinue an avalanche control policy that costs the park $325,000 each season. In winter, park service employees fire artillery shells from a 105 mm howitzer or hand drop explosives from helicopters in an effort to clear the pass's 20 avalanche runs. But last year only 90 snowmobiles crossed the pass, which is located just inside Yellowstone's east entrance, bringing the bill to $3,600 per vehicle. The groups, which also include the National Parks Conservation Association, the Sierra Club, and the Natural Resources Defense Council, have pointed to the 1994 death of park ranger Bob Mahn, who died during a patrol of the pass. Two NPS environmental impact studies also concluded that even with avalanche control "the risk [of keeping Sylvan Pass open] remains extreme and unavoidable.” At this point, Yellowstone officials have no plans to stop shelling.
Read more at NewWest.com