Moses Coulee glaciation on the Waterville Plateau includes polished and striated bedrock, glacial erratics, drumlinoid topography, eskers, moraines, meltwater channels, and glacial till. The Withrow Moraine complex marks the maximum southern extent of the Okanogan Lobe, and a series of recessional moraine complexes represent retreating ice margins. Ice damming of the Columbia River formed Glacial Lake Columbia and Lake Spokane, larger lakes than Lake Roosevelt, which is currently backed up in the same location behind the Grand Coulee Dam. A precursor to glacial-flood-cut Moses Coulee existed prior to the glacial floods as a drainage basin with a number of side streams, draining
Laser light show (Grand Coulee Dam) in 2014. It will replace the current laser show "Water and Life" which has been running for the past 24 seasons. The new show is being prepared by LumaLaser of Eugene, Oregon. 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