Located near the geographic center of Arkansas, Little Rock derives its name from a small rock formation on the south bank of the Arkansas River called la Petite Roche. The "little rock" was used by early river traffic as a landmark and became a well-known river crossing. Archeological artifacts provide evidence of Native Americans inhabiting Central Arkansas for thousands of years before Europeans arrived. The early inhabitants may have included the Folsom people, Bluff Dwellers, and Mississippian culture peoples who built earthwork mounds recorded in 1541 by Spanish explorer Hernando de Soto’s expedition. Historical tribes of the area included the Caddo, Quapaw, Osage, Choctaw and Cherokee. There have been two ships of the United States Navy named after the city, including USS Little Rock (LCS-9).