Elephant Butte Lake State Park is a state park of New Mexico, United States, located 7mi north of Truth or Consequences along the shore of Elephant Butte Reservoir. It is the largest state park in New Mexico and surrounds the state's largest reservoir. The 36000acre reservoir, created in 1916 across the Rio Grande, is 40mi long with more than 200mi of shoreline.Recreation at Elephant Butte Reservoir is managed by the New Mexico State Parks under agreement with the United States Bureau of Reclamation. Elephant Butte Dam, constructed between 1911 and 1916, was a major engineering feat in its day. The enormous concrete dam is the major feature of the Elephant Butte National Register Historic District. New Mexico State Parks operates a visitor center that contains information on the construction of the dam. There are 3 developed camps on the lake, with over 200 camping and picnicking sites, concession-operated marinas, and stores.Although the park is named after an elephant-shaped butte located at the head of the dam, an actual stegomastodon fossil was discovered there in June 9, 2014.