In 1878, Ed Muldie and his three sons leave Kentucky to take advantage of the free land offered by the United States government through the Homestead Act. They settle in Nicodemus, Kansas, and build a dugout home to live in for the winter. During the harsh winter, the people of Nicodemus are saved from starvation by the Osage Indians who bring them food. The following spring, Ed Muldie leaves his boys with the people of Nicodemus while he travels ahead to find a place to build a home. While living by themselves in the dugout, the three boys narrowly escape a prairie fire. When a letter from their father finally arrives, the three boys must travel 150 miles by themselves to reach their new home.