Burlington is the most populous city in the U.S. state of Vermont and the seat of Chittenden County. It is located 45 miles south of the Canada–United States border and 94 miles south of Canada's second most populous city of Montreal. The municipal population was 42,452 according to a 2015 U.S. census estimate. It is the least populous city in the U.S. to be the most populous within a state.A regional college town, Burlington is home to the University of Vermont and Champlain College, a small private college. Vermont's largest hospital, the UVM Medical Center, is located within the municipal limits. In 2015, it became the first city in the U.S. to run completely on renewable energy.