CHEYENNE, Wyo. (AP) — Voters for the first time will decide between four women as the major party candidates for U.S. House and Senate in Wyoming.

Republican former U.S. Rep. Cynthia Lummis faces University of Wyoming ecology professor and climate activist Merav Ben-David in the race for a Senate seat held by Republican Mike Enzi, who is retiring after four terms.

Wyoming hasn’t had a U.S. Senate vacancy since Republican Craig Thomas died in 2007.

Democrat Lynnette Grey Bull, a Northern Arapaho tribal member and Global Indigenous Council vice president, seeks to deny Republican Rep. Liz Cheney a third term as Wyoming’s lone representative in the U.S. House.