Judith Gap was named for its location in a gap between the Snowies and the Little Belt Mountains. The area served as the easy way to the Judith Basin. At one time it was a division point on the Great Northern railroad as attested to by the remains of the coal chute and water tanks.
Because of the railroad, it was a busy grain shipping center as well. The path through the gap was originally established by Indian warriors and hunters defending or seeking the rich hunting grounds of the Judith Basin. It was later used as a vital route by freighters, cattle drivers, prospectors, hunters, and settlers passing northward into the Judith Basin or southward to the Yellowstone or Musselshell valleys. It was named for the nearby Judith River which was named by Lewis and Clark.