• Sunset Crater Volcano National Monument

    Sunset Crater Volcano

    National Monument Arizona

Soils

Lichen growing on lava rock

Reddish lichen growing on this lava rock hastens the formation of new soil

Before this volcano erupted, there was fertile soil here - enough to support a group of prehistoric farmers and their families. Their fields are buried now beneath hundreds of feet of cinders, and the landscape has changed forever. New soil is forming, but it’s a slow and precarious process. Weathered particles and bits of organic matter must accumulate between the cinders in order for most plant species to germinate, survive, and reproduce successfully.

In the early stages of soil formation, this process is easily disrupted. Any disturbance can dislodge the particles and cause them to sift deeper into the cinders, where they may be out of reach for use by plants; plants already established may also be dislodged. For this reason, it is important for visitors to stay on designated trails.

Did You Know?

Sunset Crater penstemon in bloom

The Sunset Crater penstemon (Penstemon clutei) is found only on cinder deposits within the San Francisco Volcanic Field, including Sunset Crater Volcano National Monument, in northern Arizona.