Spiro is a town in Le Flore County, Oklahoma, United States. It is part of the Fort Smith, Arkansas-Oklahoma Metropolitan Statistical Area. The population was 2,164 at the 2010 census, a 2.8 percent decline from 2,227 at the 2000 census.Developed as a railroad station in an agricultural area in the late 19th century, the small town is notable for its proximity to the Spiro Mounds. This is a Mississippian culture center that was active from about 900 to 1450 CE that was part of a culture in Eastern Oklahoma and Western Arkansas. Today the 80-acre site with several earthwork mounds is preserved as Oklahoma's only State Archeological Park and one of North America's most important archaeological sites. It is the westernmost site of the expansive Mississippian culture, which had associated centers through the Mississippi and tributary river valleys.