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
Coulee City, Washington males. The median income for a household in the town was $25,938, and the median income for a family was $42,500. Males had a median income of $31,375 versus $17,250 for females. The per capita income for the town was $14,411. About 14.9% of families and 22.1% of the population were below the poverty line, including 29.2% of those under age 18 and 11.7% of those age 65 or over. Coulee City, Washington Coulee City is a town in Grant County, Washington. The population was 562 at the 2010 census. The town was named after nearby Grand Coulee. Coulee City