Located on the state lines of Texas and Louisiana, Miller County is home to four Masonic lodges. Texarkana is the county seat and was once called "The Gateway to the Southwest" in reference to travelers moving into Texas.

Ironically, Miller County is cut off from the rest of Arkansas by the Red River. At one time settlers going to Texas considered themselves in Texas when they crossed the Red River at Fulton, Arkansas. Some early maps show Miller County as part of the Texas; however, by the time of the Texas Revolution, most maps and governments agreed that Miller County was firmly part of the State of Arkansas.