From the Canadian border the tour dips down to Spokane, crosses a palisaded metropolitan area, and winds southwesterly through a country of lakes, parks, escarpments and wooded hills, until it sweeps down into the “Big Bend” wheat-lands. Continuing southwesterly, US 395 descends through a succession of lava-walled coulees and breaks into an open, semidesert country, where the Snake River joins the Columbia, southeast of Pasco.
A part of the area traversed by this route, adjacent to the Columbia River on either side of Kettle Falls, was drastically affected by the backwater from Coulee Dam. This dam across the Columbia River, part of the Columbia River Basin project, created a vast, 130-mile long artificial lake. The depth of this lake, directly behind the dam, is 377 feet, lessening gradually up the river as the ground rises. The waters covered not only the Columbia itself but also tributary streams such as the Kettle, San Poil, and Spokane rivers; forming a shore line estimated at 5,000 miles, extending irregularly far up many valleys, canyons, and gullies.