Underneath Main Street in Lewistown, Mont., residents like to float on inner tubes down Spring Creek. Ian Gray/Mapping Main Street hide caption

itoggle caption Ian Gray/Mapping Main Street

The end of Main Street in San Luis, Ariz., is a border crossing station that connects the city to San Luis Rio Colorado in Mexico. Jesse Shapins hide caption

itoggle caption Jesse Shapins

East Main Street in Chattanooga. Courtesy James Burns hide caption

itoggle caption Courtesy James Burns