Grand Coulee Columbia Rivers pathway and onto the southern plateau creating an ice dam. This dam backed up the waters of the Columbia into Glacial Lake Columbia and later during the Missoula Floods forced those waters into eastern Washington, creating the Scablands. The river at Grand Coulee found no existing valley and thus forged its own pathway across the divide, creating the Upper Coulee. The plateau is not level, but is marked with wrinkles and upfolds of the basalt. The diverted waters of the Columbia, encountered the monoclinal flexure, a steep warping up of toward the northwest. Lake Columbia topped the ridge
Plum Coulee Plum Coulee Plum Coulee is an unincorporated urban community in the Municipality of Rhineland within the Canadian province of Manitoba that held town status prior to January 1, 2015. It is west of Altona, one hour southwest of Winnipeg and half an hour from the United States border. It is also the former home to the Plum Coulee Xpress hockey club. It has a man-made beach located in town. Philanthropist Saidye Bronfman was born in Plum Coulee. Plum Coulee's population of 800 is growing through land development. Working with local land owners, the former Town of Plum Coulee developed a