Aerial Tour of Ice Age Floods “A Birds eye View”

The geology of the Tri-Cities area is very unique in that it consists of a basalt and lava landscape carved by the great Ice Age Floods. During the largest floods the Tri-Cities lay under 900 feet of floodwater (i.e., Lake Lewis) that backed up behind the hydraulic constriction at Wallula Gap. During this time the tops of the local hills (e.g., Badger and Candy Mountains) were “islands” poking out above Lake Lewis. The high water mark for the floods in the Pasco Basin (1200 ft elev.) is based on the maximum observed height of erratics, which is coincident with channeling at Wallula Gap.

The Wallula Gap (near Tri-Cities) is one of the most significant natural features during the Ice Age Floods. All the floodwaters from glacial Lake Missoula after having spread out over hundreds of miles of the Channeled Scabland were funneled through this single narrow opening only a few miles wide. More water entered the Gap than could pass through, so the water backed up. This forced floodwaters up the Yakima and Walla Walla river valleys, submerging Yakima and Walla Walla under hundreds of feet of water while the backwater rose to around 900 feet over the Tri-Cities.

Call us now to book your Ice Age Floods Aerial Adventure!



Be sure to visit the Ice Age Floods Institute website at for more information on the Ice Age Floods and how they’ve shaped our landscape!

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