With the closing of Grand Coulee Dam’s gates in 1942, Franklin D. Roosevelt Lake (or Lake Roosevelt for short) was created.

The waters of the Columbia River behind Grand Coulee rose 380 feet, creating over 600 miles of shoreline. The length of the lake is over 150 miles, extending from Grand Coulee dam to near the Canadian border. The width of the lake generally varies from one half to one mile from the dam to Kettle Falls, which is about 100 river miles. The lake then narrows considerably as it reaches up to Northport and the Canadian border.

The size of Lake Roosevelt, however, only begins to tell the story of a water and land area that is unique in many ways. This section contains a brief overview of how the area’s geography, cultures and economies change and shift from North to South and East to West.

The waters of Lake Roosevelt fill an immense valley and gorge.

During the ice age floods, glaciers from the north descended south and created large valleys. Huge lakes extending well into Montana formed behind the ice. When the ice dams collapsed, there were torrents of flooding that have no parallel in size and scope today. These floods further shaped the gorge. Indeed, vertical walls more than 800 feet high were created.

Beyond the ice age floods, the physical characteristics of the lands reflect the crossroads of three distinct geographic provinces: the Okanogan Highlands, the Kootenay Arc, and the Columbia Plateau. As described by the Washington State Department of Natural Resources:

The Okanogan Highlands province is situated east of the Cascade Range and north of the Columbia Basin. To the east and north, the highlands extend into northern Idaho and southern British Columbia, respectively. They are characterized by rounded mountains with elevations up to 8,000 feet above sea level and deep, narrow valleys. The Columbia River divides the Okanogan Highlands into two geographic regions: to the east of the river are the Selkirk, Chewelah, and Huckleberry Mountains; to the west are the Kettle, Sanpoil, and other mountains.

The eastern portion of the Okanogan Highlands contains the oldest sedimentary and metamorphic rocks of the state. Precambrian Belt Supergroup, Windermere Group, and Deer Trail Group metasedimentary rocks extend from British Columbia south to the Columbia River. The nation's second largest magnesium operations are located near Addy, in Stevens County.

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The northern areas of Lake Roosevelt receive about 17 inches of rain a year.

This rainfall supports dense growths of Ponderosa Pine and Douglas-fir. Grasslands, Alder, willow, hazelnut, and black cottonwood are common along the river and its tributaries.

Moving south, however, the climate becomes far more arid. In the mid-lake area there is a transition from Ponderosa Pine to sage-steppe. Bluebunch, wheatgrass, hard fescue, and forbs such as balsamroot, northern buckwheat, brittle prickly pear, alum root and lupine are common here.

By the time the river/lake reaches Grand Coulee dam, average annual precipitation is only 10 inches. This precipitation occurs mostly in the winter and spring. The summers are hot and dry. So instead of dense forests, the environment is that of a high desert where shrub steppe species like sagebrush and bitterbrush predominate.

Five counties and two Indian reservations touch Lake Roosevelt.

Moving clockwise and south from the northwest, there is Ferry County, Stevens County, the Spokane Indian Reservation, and Lincoln County. At Grand Coulee Dam there is the northeast corner of Grant County and (now heading north to complete the circle) the Colville Indian Reservation and Okanogan County.

In Ferry County, the land is heavily forested and relatively mountainous. In keeping with its character, timber and mining activities have been the backbone of the local economy for the past one hundred years. With layoffs at an area mine in 2002 and possible closure of a local lumber mill, natural resource industries are declining. This area is very thinly populated, with less than 4 persons per square mile.

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Indian Reservations

Washington State Counties

Washington State

Notes: Except as shown by asterisk, all data from U.S. Census