Last February, Jaki Good Miller and I flew into Albuquerque and headed out on a five hour drive to one of my favorite places on Earth, Monument Valley. We had hoped to get to the 13-mile marker north of the Valley to get a sunset shot of the famous road shot made famous in the movie, Forrest Gump. Our timeframe was tight and we weren't sure we would make it. Of course, landscape photographers can be easily distracted when the light is terrific and a new and different subject appears. Cue in the volcanic plugs that we spotted about a half-mile south of the Valley. The biggest plug was the 1,500 foot high Agathla Peak, which I posted last year. In the fields around the peak there were a number of smaller volcanic plugs, like this one that made nice subjects themselves.
So, what is a volcanic plug? I'll be honest, I never heard of the term before and only learned about them when researching Agathla Peak. Simply put, they are a volcanic rock created when magma hardens within a vent on an active volcano. A plug can cause a build-up of pressure if molten magma is trapped beneath it, which could lead to an explosive eruption. I don't know whether that is the case here, but I was interested in other volcanic plugs in the US. Turns out, two places that I have visited before, Morro Rock in California and Devils Tower in Wyoming (featured in the movie Close Encounters of the Third Kind) are volcanic plugs. Who knew?