The Columbia River Gorge began forming as far back as the Miocene (roughly 17 to 12 million years ago), and continued to take shape through the Pleistocene (2 million to 700,000 years ago), forming a huge basalt plain.
But the Columbia River Gorge wasn’t created by volcanic flows or giant floods. The river was here before the mountains. The river cut a path as the land was gradually pushed up by tectonic forces.
During a 10–15 million-year period, lava flow after lava flow poured out, eventually reaching a thickness of more than 5,900 ft.
The basalt cooled, creating hexagonal shapes as it shrunk. As the molten rock came to the surface, the Earth’s crust gradually sank into the space left by the rising lava. The Cascade Mountain range was pushed up later as the river carved a path through the rock over millions of years.
The Missoula Floods were a series of cataclysmic floods that swept periodically across eastern Washington and down the Columbia River Gorge at the end of the last ice age, between 15,000 and 13,000 years ago.
The water and ice carried giant boulders called “erratics” and deposited them all over Portland and the Willamette Valley.
Lake Missoula, a prehistoric lake in western Montana, existed periodically at the end of the last ice age and contained about 500 cu miles of water, half the volume of Lake Michigan.
The periodic rupturing of the ice dam resulted in the Missoula Floods – cataclysmic floods that swept across eastern Washington and down the Columbia River Gorge approximately 40 times during a 2,000 year period.
The flood started in the Idaho panhandle as a wall of water 2,000 feet high, bursting through the remnants of a glacial dam at 65 miles an hour. In volume, the deluge thundering across the Pacific Northwest was 10 times the combined flow today of all the rivers on Earth.
After a week or two, the flood subsided to normal river levels, the land around stripped bare. Halting recovery began in the ensuing years, vegetation getting a toehold on ravaged floodplains. Then, 30 to 50 years later, another flood would come.
This cataclysm happened as many as 100 times over the next 3,000 years, and helped shape the canyon we see today. Coulees are gouged-out canyons in the high desert of central Washington that now carry little or no flowing water. The two most spectacular are Moses Coulee and Grand Coulee.
Palouse Falls lies upstream of the confluence with the Snake River and Palouse River. The Palouse Falls and surrounding canyons were created when the Missoula Floods overtopped the south valley wall of the ancestral Palouse River, diverting it to the current course to the Snake River
Dry Falls, on the Upper Grand Coulee, channeled water at 65 miles per hour over its 400-foot rock face. It is estimated that the falls were five times the width of Niagara with ten times the flow of all the current rivers in the world combined.
Let’s bring the Missoula Floods back. In VR.
Drones can make 3D maps. Easy. The Drone Deploy app (Android and IOS) flies the drone for you. First you draw a flight pattern on Google Maps. Then it takes over and flies the drone for you, taking hundreds of photos automatically. Lastly you upload the photos to their cloud server. Their cloud server makes the 3D model from your drone photos.
The result: a giant, zoomable 3D map. You can view it much like Google Earth, but it uses current photos and has more 2D and 3D resolution. Also works with VR headsets. Cool.
Give them an experience.