Grand Coulee Grand Coulee The Grand Coulee is an ancient river bed in the U.S. state of Washington. This National Natural Landmark stretches for about 60 miles (100 km) southwest from Grand Coulee Dam to Soap Lake, being bisected by Dry Falls into the Upper and Lower Grand Coulee. The Grand Coulee is part of the Columbia River Plateau. This area has underlying granite bedrock, formed deep in the Earth's crust 40 to 60 million years ago. The land periodically uplifted and subsided over millions of years giving rise to some small mountains and, eventually, an inland sea. From about 10 to
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