Marshall is the largest city in and county seat of Searcy County in Arkansas, United States. It is located in the Ozarks at the foot of the …Marshall is the largest city in and county seat of Searcy County in Arkansas, United States. It is located in the Ozarks at the foot of the Boston Mountain Range 10.5 mi south of America's first National River, the Buffalo National River. Marshall serves as a hub for area tourism including camping, floating, hiking, bicycling and Dark Sky viewing.