The Interesting Geology of Bend, Oregon (Richardson’s Rock Ranch & Newberry National Volcanic Monument) |

Recently, I spent a week in Bend, Oregon enjoying the area’s interesting geology. I dug for Oregon Thundereggs, Oregon’s state mineral, at Richardson’s Rock Ranch, and visited Lava River Cave at the Newberry National Volcanic Monument.

Oregon Thundereggs (Richardson’s Rock Ranch)

Thundereggs are like geodes, except they’re filled with minerals like agate, jasper, and opal. They form within layers of volcanic ash.

I dug for mine at Richardson’s Rock Ranch, which is about an hour outside Bend.

Unfortunately, Richardson’s Rock Ranch closed their pits to digging in 2019, but this video from the Mining America YouTube channel shows what the experience of digging for thundereggs was like pre-2019.

To get them out of the ground, I used a sledgehammer, a rock chisel with thumb guard, and a plastic brush to remove debris.

I dug in three beds at Richardson’s (including the Priday Agate Beds), and found thundereggs filled with banded agate, plume agate, and common opal.

While I waited for my thundereggs to be cut, I wandered around and found a nest of barn swallows under a porch roof.

Check out the photos below of the best thundereggs I dug up!

Lava River Cave (Newberry National Volcanic Monument)

Laver river cave is a mile-long cave and the longest lava tube in Oregon. It was originally discovered by settlers in the late 1800s.

The entrance to the cave is quite bright, but you quickly descent into total darkness.

There were interesting features on the walls and ceiling, though not as distinctive as ones found in the lava tubes at Craters of the Moon National Monument.