Neenach Volcano

August 23, 2011 by Evan Davis

…a venture I took looking for the missing half of a volcano.

What?

You heard me, the missing half of a volcano. My mother and I were driving south on our way to the Grand Canyon about 25 years ago and we saw a sign for a National Monument. We had never heard of it, but it was of enough national importance to reserve the land and devote federal dollars to it, so we took a detour. Turns out there was a Volcano in California 23 million years ago. No surprise there, but it was 195 miles south.

So, why is a monument here?

Somewhere in that 23 million years a fault, like the San Andreas, formed. Right through the middle of the volcano. The west side of the fault moved north until the halves were 195 miles apart. At the north half (Pinnacles National Monument N 36° 29′ 55.54″, W 121° 12′ 9.02″)*, erosion has left behind interesting, vertical rock formations that climbers love. The southern half (Neenach Formations) is a bunch of boring rocks on a hill (N 34° 44′ 58.30″, W 118° 35′ 51.62″ & N 34° 46′ 32.43″, W 118° 40′ 12.08″)*.

So why now?

I was thinking about that trip and the coolness of the volcano’s story so I decided to start hunting for it all again. My search for the National Monument was short since it’s well documented, but my search for the other half took a little bit more. First off I didn’t know if it was north or south. My knowledge of the San Andreas fault system told me that Pinnacles should be north of the other half.

Where was it?

I finally found help in a Geocache listing. It had an image of the location from a country road and it was rather anticlimactic, but there it is. *All global coordinates manually searched and found using Google Earth.

Update: There it is.

And now it’s somewhere else. In my search I found nothing on the southern half on wikipedia so I decided to create an article there as well. Now when you look for the ‘Neenach Volcano’ you’ll know that I contributed.