Established Dec. 31, 1987.

Source: U.S. National Park Service

El Malpais National Monument is composed of nearly 1,500 square kilometers of mainly Quaternary lavas. Pictured here is a typical exposure of El Calderon basalt. This basalt is among the oldest in the monument, probably over 100,000 years old. Occurrences are restricted to northern areas.

This lava blister in Twin Craters basalt has partially collapsed to form a small cave. Twin Craters overlies El Calderon material in the north-central portion of the monument. This lava is at least 15,800 years old, and is most likely older.

Twin Craters basalt.

Northeast wall of Bandera Crater. Lava from this vent has been dated at about 10,000 years making it the second youngest in the monument. It is a 23 mile long flow of alkali basalt with both aa and pahoehoe textures. The cone itself rises about 150 meters above the surrounding area. The crater is one kilometer in diameter and about 240 meters deep.

Northwest wall of Bandera Crater. Erosion is gradually causing the crater to fill with loose lava and cinder.

The breach in the southwest wall of Bandera Crater. Lava flowed through here to the south-southwest, then turned southeast. Contained in this flow is a 17 mile long lava tube complex, one of the longest in North America.

The beginning of the Bandera Lava Tube. Much of the tube has collapsed as in this picture, but some areas have not. Such areas provide good opportunities for caving.

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