YVTC MESA Students Visit Dry Falls - 8/1/2006

Dry Falls was created by the bursting of an ice dam. The waters came from “Glacier Lake Missoula”, a lake that held about the same volume as Lake Ontario. Once the dam broke it eroded everything in its way. Missoula floods covered land from Washington, Idaho and Oregon. It was so powerful that it ripped through walls of basalt and scattered it for hundreds of miles. They are also called iceberg deposits. These deposits can be seen as you drive along the road on the way up to Dry Falls.

The floods lasted for weeks and reoccurred every 50 years leaving carved landscapes behind. What we see today is hundreds of small lakes, jagged terrain, and many canyons.

Everywhere the students went they saw the result of the Missoula Floods. There were towers of basalt all over. The basalt was there millions of years before the floods when the area was covered in volcanic activity. Basalt was created from the cooling of repeated lava flow. Basalt covered much of the Northwest. Geologists named it the “Columbia Plateau”. As you can see, the flood blasted right through.

Sunnyside and Pasco High School students got to see the results of this massive flood first hand. The Geological information about this flood is part of the curriculum for the 9th grade Physical Science. Actually walking the site and visiting the affects of this flood sure make remembering the details much easier when taking a test.