Mammoth Spring State Park is a 62.5-acre (25.3 ha) Arkansas state park in Fulton County, Arkansas in the United States. The park is located surrounding National Natural Landmark of the same name to provide recreation and interpretation for visitors. The park offers fishing, boating and hiking in addition to an Arkansas Welcome Center and restored 1886 Kansas City, Fort Scott and Memphis Railroad depot operating as a railroad museum. The site became a state park in 1957, but the park continued to add area until 1975.