[1] The reservoir is part of the Rio Grande Project to provide power and irrigation to south-central New Mexico and western Texas.

The reservoir, dam, and surrounding area are named after a volcanic core, "Elephant Butte," similarly to Devils Tower, in Wyoming.

[3] A large construction community sprang up, which included two worker camps, railways, water tanks, cableway systems, and the former administration building of the Bureau of Reclamation.

Moreover, many centuries-old communities and farming villages were "obliterated" by the filling of the reservoir and now lie at the bottom, including complete stone structures.

[3] When the reservoir started filling in 1915, irrigation use downstream was much more limited than today, which allowed the lake to remain relatively full.

That was the deepest highstand on record and stained the inundated landscape white with gypsum and other minerals and deposited sediments in the surrounding hills.

[8] When the lake falls over 10 meters (30 feet) below maximum capacity, the ruins of the old machine shop and power plant are out of the water.

[9] Located near the southeastern shore, the 3000 square-foot concrete structure was once believed to be the remnants of the old field hospital that served the frequently-injured dam construction crew.

[3] In 2014, a group celebrating a bachelor party on the exposed sediments of the lake discovered the head and tusks of a 3.2-million-year-old stegomastodon, a relative of true elephants, in excellent condition.