Snow covers the entrance sign to Glacier National Park Dec. 11, 2012, in West Glacier, Mont. Glacier officials are concerned about the effects of oil and gas development on the Blackfeet Indian reservation, and are asking for an in-depth study on the environmental impacts. Blackfeet tribal officials say they are complying with all requirements before drilling and they bristle at the suggestion they can't develop their resources safely. (AP Photo/Matt Volz).