What river features the Grand Coulee Dam?

The Grand Coulee Dam is located on the Columbia River in Washington State. This river is notable for its significant size and flow, ranking as the fourth largest river in North America by discharge and the largest river flowing into the Pacific Ocean from North America.

The construction of the Grand Coulee Dam, which began in 1933 and was completed in 1942, was part of a larger effort to harness the river's waters for irrigation, power generation, and flood control. The dam plays a critical role in the Columbia Basin Project, which has greatly expanded the agricultural capacity of the region by providing irrigation to arid lands.

In terms of the other rivers mentioned, the Mackenzie River is located in Canada and does not have any relation to the Grand Coulee Dam, while the Ohio River and the Missouri River are also located in different regions of the United States and have distinct histories and geographical significance unrelated to the Grand Coulee.