According to the U.S. Census Bureau, Beaver County has a total area of 1,818 square miles making it the fifth-largest county in Oklahoma by area. Located within Beaver County are the Beaver Sand dunes.
Cimarron County has a total area of 1,841 square miles making it the fourth-largest county by area. Black Mesa, which is the highest point above sea level in all of Oklahoma, is located in Cimarron County.
Dewey County has a total area of 1,008 square miles. Most of the county is located in the Gypsum hills area.
Ellis County has a total area of 1,232 square miles. Covering most of the county is the Great Plains region.
Harper County has a total area of 1,041 square miles. The county contains rocky, red canyons as well as high plains and rolling hills.
Texas County has a total area of 2,049 square miles making it the second-largest county by area. The area is mostly flat but does house a few rolling hills. The area has been named the Red Carpet Country by the Oklahoma Department of Tourism.
Woods County has a total area of 1,290 square miles. The County is located along the Kansas boarder.
Woodward County has a total area of 1,246 square miles. Located in the County are gypsum hills. Tourist attractions in the area includes the Alabaster Caverns State Park and the Boiling Springs State Park.