I think in Yellow Stone Park they should ban snowmobiles if people don’t know how to ride them. They should have park rangers behind them watching them ride. They should also put up signs on trails that have bison that cross. This will alert the riders to slow down and watch for bison crossing. They should ban snow shoes because if they walk on ice they might  crack the ice and cause them to fall. They should ban snow skying in Yellow Stone because it could cause people to fall off into a deep cliff or break a bone.