Collier's New Encyclopedia (1921)/Columbia River

COLUMBIA RIVER, after the Yukon the largest river on the W. side of America; rises in British Columbia, on the W. slope of the Rocky Mountains, near Mounts Brown and Hooker, in about lat. 50° N.; has a very irregular course, generally S. W. through Washington; forms the N. boundary of Oregon for about 350 miles; and enters the Pacific by an estuary 35 miles long and from 3 to 7 wide. Its estimated length is 1,400 miles. The area drained by this stream and its affluents, of which the largest are Clarke's Fork and the Snake river (with very remarkable cañons), has been computed at 298,000 square miles. The river is broken by falls and rapids into many separate portions, and the ingress and egress are embarrassed by a surf-eaten bar. Still, it is open to steamboat navigation from its mouth to the Cascades (160 miles), and goods are carried past the obstruction, for 6 miles, by railway; the next reach, of 50 miles, extends to Dalles, where another railway, of 14 miles, has been constructed past the Great Dalles channel; and immediately above this are two sections, of 185 and 250 miles respectively, navigable for small steamboats. The extraordinarily abundant salmon-fisheries of the Columbia have been largely developed.