Beginning nearly 15,000 years ago the Columbia Plateau was transformed by the successive Missoula glacial outburst floods.

Much of the flood water made way down the Columbia river Channel where a 'choke-point' known as Wallula Gap caused the restriction of flow.

These flood deposits which were deposited in large quantities in short amounts of time changed the ground elevation within Badger Canyon causing the Yakima River to re-route north of Red Mountain and enter the Columbia River by present-day Richland.

[9] The Yakima River Basin consists of approximately 6,150 square miles (15,900 km2) located in south central Washington State.

Agricultural land totals 1,000 square miles (2,600 km2), including irrigated pastures, orchards, grapes, hops, and field crops.

[4] Forested areas in the northern and western portions of the basin occupy approximately 2,200 square miles (5,700 km2) and are used for recreation, wildlife habitat, timber harvest, grazing, and tribal cultural activities.

Range lands comprise about 2,900 square miles (7,500 km2) and are used for military training, grazing, wildlife habitat, and tribal cultural activities.

In addition to irrigated agriculture, the major economic driving forces include timber harvest and processing, cattle, and outdoor recreation.

The proximity to high population areas of the Puget Sound has caused a rapid increase in the demand for outdoor recreational experiences in the basin.

The irrigation system in the Yakima's watershed causes periods of both severe river dewatering and elevated flows, relative to the historic streamflow regime.