Where Are We? ... and Why?

So far there hasn’t been much in the way of adventure in 2013.  Spring passed without a road trip, as work dictated otherwise.  However I managed to sneak away for a long weekend recently, and discovered this very interesting area:

From Google Earth; click on photo for more detail.

Few people would consider this part of the country a geo-destination ...... but it is.

Sparky walks in the tracks of giants.

We found siliceous gravels from events far away and long ago (actually fairly recently, geologically-speaking).
In some places there were lots of plants ...... even on buildings! ...... but they were pretty sparse where we hiked.And there was sky everywhere -- immense, blue and beautiful.

Geo-challenges always attract lots of readers, but rarely does anyone respond to the challenge.  If you think you know where we were, please leave a Comment.  I will publish any received next week, along with the rest of the story.  [Update:  the rest of the story is now available here.]