Approximate location — plotted from published sources, not a site visit, and not a guarantee of access.
National Natural Landmark (1975) maar crater—an explosive volcanic pit with little cone-building—set in the Chihuahuan Desert basin between the Potrillo Mountains and the Rio Grande. Roughly 1.7 miles long and hundreds of feet deep; famous for mantle-derived olivine-rich volcanic bombs. Rim lands are BLM within Organ Mountains–Desert Peaks National Monument; crater floor includes private inholdings—view and hike the public rim only.