Fremont County is a county in the U.S. state of Wyoming. As of the 2020 United States census, the population was 39,234, making it the fifth-most populous county in Wyoming. Its county seat is Lander.

Big Horn County is a county in the U.S. state of Wyoming. As of the 2020 United States census, the population was 11,521. The county seat is Basin. Its north boundary abuts the south boundary of Monta