Rainbow Mountain in Madison County, Alabama, takes its name from early settler Elisha Rainbolt, who arrived around 1810, with the modern name evolving over time. The mountain is part of Alabama’s Highland region and is composed mainly of Mississippian sedimentary rock, especially limestone, capped by Hartselle Sandstone. Fossils such as Archimedes, rugose corals, and crinoids reflect the era when this area lay beneath the Tethys Seaway. Its karst landscape includes sinkholes and small grottos, and reported Paleoindian arrowheads indicate human use long before nineteenth-century settlement. Today, part of the mountain is protected as the 65-acre Rainbow Mountain Nature Preserve with trails for public exploration.