Palouse River & Palouse Falls
More blue sky and warm weather. The day started off with options to explore the Palouse River via kayak or Zodiac, or a short bus trip to Palouse Falls. The views from the river provide a chance to see the Columbia River basalts up close. What I found impressive were the presence of vesicles in the basalt. They look like worm holes but in fact are frozen bubbles formed as gas exsolved from the molten lava.
The trip to Palouse Falls gave us the first opportunity to see the top of the Columbia Plateau. Prior to this time, we only had an “edge on” view of the basalt layers. The lava was so fluid when it erupted that it created a relatively flat upland surface. This accounts for why flood basalts are sometimes called plateau basalts.
At Palouse Falls, we saw a very small river flowing through a huge box canyon. The plunge pool below the falls was also huge compared to the tiny trickle of water flowing over the falls. The channel and falls were formed 15,000 years during the Missoula Floods. In fact, the flood waters were at times higher than the channel, and spread out over a huge part of the plateau. As a result, the water flowed through many channels at the same time, much like the braided river channels you see in high-water rivers.
