Port Alsworth is a census-designated place located in the U.S. state of Alaska. It is within in Lake and Peninsula Borough. It is approximately 100 miles in the southwest Anchorage on private land within Lake Clark National Park and Preserve and the site of the National Park's field headquarters. The population was 159 at the 2010 census. In 1950, Port Alsworth was founded by Babe Alsworth and Mary Alsworth. The total area is about 22.8 square miles at 60°12′30″N 154°18′24″W. It is elevated by 253 feet. As of the census of 2010, Port Alsworth has a total population of 159. The population density was 7.0/sq mi. The temperature of Port Alsworth is continental subarctic climate. It has Zip code 99653.