New Mexico Lava Beds Along I-40



The first two photos show the McCarty’s Lava flow beside Rt. 124 (historic Rt. 66) about 4 miles east-southeast of I-40 exit 89 between Grants and McCarty’s, New Mexico. The upper layer is full of gas bubbles. [November photos] – © Dave Spier

New Mexico’s El Malpais Lava Beds at I-40 — © Dave Spier

East of Grants, New Mexico (USA), Interstate 40 passes through the north end of the El Malpais lava fields. (Malpais is Spanish for “badlands” and was used by early map makers to describe volcanic terrain.) The area is related to the Zuni-Bandera volcanic field. Of the numerous basalt flows, two reached the present I-40/Rt. 124 highways. The youngest, the McCarty flow, is a mere thousand years old. Stop at the mile 93 rest areas for a closer look or drive Rt. 124 parallel to the interstate. The older Calderon flow reached to Grants and can be accessed from the exits. The small volcanoes at the source are 20-30 miles southwest in El Malpais National Monument which is reached by Routes 117 and 53.

On Google Earth 6.2, you can zoom in on I-40 between Grants and McCarty’s to the southeast. (Exit 89 GPS co-ords are 35° 05′ 04.82″ N, 107° 46′ 12.77″ W)  The geologically “recent” McCarty’s lava flow is an irregular black line heading north along the west side of Rt. 117 at the base of the Las Ventanas Ridge, then widening and “pooling” east of exit 89 (where Rt. 117 begins at I-40), then streaming east-southeast along Rt. 124 (Historic Rt. 66) most of the way to McCarty’s. The dissected north rim of the McCarty’s Mesa is south of Rt. 124 and formed the southern barrier constraining the lava. The older Calderon lava flow is an irregular brownish-gray blob west of exit 89 on the Google aerial view.

The basalt is similar to the dark lava flows that form the Moon’s “seas.”


This series of three photos shows the McCarty’s Lava flow on the east side of Rt. 124 (historic Rt. 66) at I-40 exit 89 between Grants and McCarty’s, New Mexico. [November photos] – © Dave Spier


Closer image of the left side in the photo above…


Closeup of the basalt in the McCarty’s Lava flow on the east side of Rt. 124 (historic Rt. 66) at I-40 exit 89 between Grants and McCarty’s, New Mexico. – © Dave Spier

Roadside Geology of New Mexico, by Halka Chronic (© 1987/reprinted 2005), published by Mountain Press

Corrections, comments and questions are always welcome at or connect through my Facebook photo page or my personal page, Dave Spier (northeast naturalist). Related topics can be found on the parallel blogs and


6 thoughts on “New Mexico Lava Beds Along I-40

  1. Otis M. says:

    East coast geo-freak, just drove (sadly with no time to spare) for the first time through NM…wow, just wow.

  2. Gringo says:

    Drove the I-40 a few times to the East coast, I-40 can be a drag to drive, but not at Grants, the lava field is outstanding.

  3. Colin Hill says:

    I just passed here today and couldn’t believe what I was driving alongside. I stopped at exit 89 by the gas station and clambered through a fence to take some photos and explore. It covers a large area and for the most part looks very dark with obvious flow patterns. So glad I happened upon it after a less than eventful day on the road. I’m no geologist so thanks for posting this and confirming my initial suspicions.

  4. cc says:

    WOW this is great… Did not even know there had been active volcanos in New Mexico… I wan in Hawaii once and got to see it there makes me really want to go back there and come back where when there is time to explore

  5. Constance Randall says:

    I drive through this area every year on my way to Arizona. It looks to be more black every year. I haven’t read about it, yet. I want to find out if it’s an active volcano. It’s an amazing thing and have never heard anyone talk about it. Next time I’m going to find somewhere to take pictures.

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