Kilbourne Hole Volcanic Crater

Kilbourne Hole is a maar volcanic crater designated a National Natural Landmark in 1975, located in southern Doña Ana County between the Potrillo Mountains and the Rio Grande. The crater measures 1.5 by 2.1 miles in diameter and reaches 443 feet deep, formed 24,000–80,000 years ago when magma encountered groundwater-saturated sediment. Managed by the BLM's Las Cruces Field Office, it features volcanic bombs with distinctive olivine glass interiors and abundant mantle xenoliths of scientific interest. Access is by vehicle on county roads, then hiking to the crater rim.