Newberry Caldera, Bend, OR June 27,2010

Newberry Caldera, located south of Bend, Oregon, is one of the largest "shield" shaped volcanoes in the lower 48 states, covering over 500 square miles.

The Glass Menagerie: The entire surface of this remarkable flow is glass, a liquid that cooled without crystallizing. The striking difference from rock to rock is due to the number and size of bubbles. Here I am sitting on a huge piece of glass.

This monument area is located along a group of faults known as the Northwest Rift zone. The most recent eruption, forming the Big Obisdian Flow 1,300 years ago, suggests the volcano is still active.

When we reached the top you could see Paulina Lake, one of the deepest in Oregon. There is another lake, East Lake, to the east of Paulina. The caldera may have originally held one large lake, much like Crater Lake, but deposits of pumice and lava divided the crater into two separate bodies of water.