Grand Coulee and highest dry falls cliff in the middle. It was created through the process of cataract recession, which included a cataract twice as high as its existing Dry Falls. Grand Coulee is two canyons, with an open basin in the middle. The Upper Coulee is filled, by Banks Lake, is long with walls tall. It links to the Columbia River at Grand Coulee Dam and leads southward, through the surrounding highlands. The entry to the coulee is above the Columbia. It began as the course of a Glacial Columbia River. The Wisconsin ice sheets Okanogan lobe extended southward across the
Laser light show (Grand Coulee Dam) Laser light show (Grand Coulee Dam) "The laser light show" at Grand Coulee Dam, which began in 1989, is one of the largest light shows in the U.S.. The 37 minute show runs daily from Memorial Day through September 30. An addition of fireworks lights up the sky above the dam each Memorial Weekend Sunday and July 4. The Grand Coulee Dam premiered its first non-laser light show in 1957. Approximately 740 flood lamps near the base of the dam lit up the dam, but not enough water flooded down the spillway for the desired effect. Lasers for the show