Similkameen River

About

Similkameen River, Washington British Columbia — 1814 David Thompson, 1858 Gold Rush, 2010s Similkameen 75-mi. Long before the river had a name on any government map, it served the region's Indigenous peoples as a primary travel corridor, hunting ground, and gathering place, threading through ancestral territory that the treaties of the 1800s, the 1830 Indian Removal Act, and the allotment era of the 1840s through 1890s would later reframe. The Canadian fur trader David Thompson reached the river's source in southeastern British Columbia during the era around 1814, charting a region that earlier maps had left blank. Four decades later the Similkameen became a corridor of a different kind: in 1858 the Cariboo Gold Rush drove thousands of prospectors north through the valley toward the goldfields of British Columbia's interior, a relatively low-altitude route that made the river a highway for ambition.

The forests came next. From the 1830s through the 1920s, the Similkameen watershed fed a regional timber industry, its stands felled by local sawmills, logging drives, and downstream lumber operations to supply both settlement and the railroad expansion reaching the region. The old-growth could not last. By 1910 the original stands were largely exhausted; a state forestry conservation movement took hold in 1915, and the establishment of state forests in the 1930s finally ended large-scale logging in the basin.

Against that backdrop of extraction rose the Similkameen's most enduring structure. Enloe Dam, begun in 1916 and finished in 1923, was built as a hydroelectric project near the river's confluence with the Okanogan. Its concrete still spans the channel more than a century later, a fixture as permanent as anything the river carved itself. The Similkameen's flows had by then already drawn scientific attention: USGS surveys began in the 1870s, gauging stations followed between the 1880s and 1910s, and state geological assessments of streamflow ran into the 1930s. Today the river is measured at USGS gauge 12442500, which records an average flow of 2,296 cubic feet per second.

The river's most contested chapter, though, is written upstream and across the border. The Similkameen shares its 2,200-square-mile watershed with southern British Columbia, and a legacy of mining endures in its headwaters: three separate facilities have polluted the upper watershed, and more than 50 abandoned mines continue to leach contamination into the water. The trouble is not confined to history. The Copper Mountain Mine, 62 miles upstream of the international border, has logged significant compliance failures and pollution violations since 2011, its owner drawing two major fines in a single November for failing to contain runoff bound for the river. Because the current carries that contamination south into Washington, the Similkameen's health has become a diplomatic question as much as an engineering one.

The response has been both scientific and cooperative. Since 2010, the Washington Department of Natural Resources, working with local watershed partnerships, has addressed more than a century of logging, agricultural, and industrial impacts through streambank stabilization, native fish restocking, nutrient reduction, and broad water-quality improvements, with Clean Water Act assessments and TMDL programs framing the ongoing work. For paddlers, the Washington reach breaks into distinct runs — from the U.S. border to Palmer Creek, Palmer Creek to Enloe Reservoir, and Coyote Falls to the Okanogan River — best run when the gauge sits between 1,150 and 3,450 cubic feet per second. The river still anchors the economies of Oroville, Tonasket, and Nighthawk, and its corridor takes in the Okanogan National Forest and Similkameen Falls.