Off along a short side trail at the Petrified Forest in Calistoga, I found an extra bit of geological history — a large ash fall left over from the eruption of Mt. St. Helena 3 million years ago. Although the entire site is scattered with concrete-like remants of the ash deposits (like the one in the image below), this spot at the end of the Meadow Trail provided a vivid picture of the volcano’s debris path.

Natural “concrete” from Mt. St. Helena

On the way to see the ash fall

No interpretive sign, but I think a huge tree once stood here