No official towns meet the criteria — there are no municipalities whose legal boundaries touch or cross the Missouri–Arkansas state line.
Define the rules strictly. Require that a town’s official polygon (its incorporated boundary from state or Census maps) actually meet the state line. Municipal boundaries are legal creations of a single state. Expect towns to be incorporated entirely inside one state, so the strict rule yields an empty list.
Understand the technical and historical reasons. State borders are fixed survey lines and local settlements grew where roads, rivers, and land made sense — not exactly on that line. State law and mapping practice keep municipal borders inside one state. High-resolution datasets (state DOT maps, USGS GNIS, Census TIGER) rarely show a town spanning two states, so strict polygon tests return no matches here. Note that cities that do straddle state lines exist elsewhere (for example, Texarkana AR/TX or Kansas City MO/KS), but the Missouri–Arkansas border has no such twin-city incorporations.
Look at useful alternatives. Compile a near-border list instead: towns and communities a short distance north or south of the line, lake and river towns in the Bull Shoals area, and official highway crossings and county maps. Check state DOT crossing lists, GNIS entries, and Census TIGER polygons for precise near-border distances. Explore those near-border towns, county pages, or a map of crossings instead of a strict “boundary-touching” municipal list.
