Blue River

About

Blue River, Colorado — 1880s Mining Era, Dillon 1963, Green Mountain 1943, I-70 Corridor. Long before the mining camps, the Blue River valley served the Ute people as a seasonal anchor in the high country. Each summer, bands moved to higher elevations to hunt elk and deer, and the valley's abundant game and mild summers made it a preferred gathering place. That pattern held until the Brunot Agreement of 1874 forced Ute cession of the region, opening the upper watershed to Anglo settlement and, within a few years, to the mining economy that would remake every drainage in the Colorado high country.

The 1859 Pike's Peak Gold Rush sent the first wave of that settlement up the Blue River valley. Prospectors working the river gravels and surrounding hillsides found enough color to anchor a permanent presence, and in November of that year Breckenridge was founded — the single most consequential date in the river's human history. The Breckenridge mining district that grew up around it drove the watershed's economy through the 1880s and into the early twentieth century, supporting extensive gold and silver operations across 680 square miles of Summit and Grand Counties.

Mining demanded timber, and the Blue River watershed supplied it. From the 1830s through the 1920s, local sawmills, logging drives, and downstream lumber operations worked the drainage, feeding both the regional timber industry and the railroad expansion that reached through the region between the 1860s and 1910s. The cutting slowed only as the resource thinned: the old-growth stands were largely exhausted by 1910, state forestry conservation began around 1915, and the establishment of state forests in the 1930s ended large-scale logging in the valley for good.

The river also drew sustained scientific attention. The first comprehensive hydrological studies of the Blue River came with USGS survey work in the 1870s through 1890s, followed by the establishment of gauging stations from the 1880s into the 1910s and early state geological streamflow assessments in the decades after. That legacy of federal survey work is reflected in USGS documentation of the drainage, including the account 'Mountains, Glaciers, and Mines of the Blue River,' which ties the valley's stratigraphy and glacial history to its mining geology. Today USGS streamgage 09046600 tracks the Blue River's discharge, averaging around 450 cubic feet per second, with optimal paddling conditions running between 200 and 1,500 CFS.

The twentieth century compressed two generations of hydrological change into twenty years. In 1943 the Bureau of Reclamation completed Green Mountain Dam, set 13 miles upstream from Kremmling, ponding Green Mountain Reservoir as part of the sprawling Colorado-Big Thompson Project. Dillon Dam followed in 1963, impounding the 3,222-acre Dillon Reservoir and anchoring the west portal of the Roberts Tunnel that carries Blue River water beneath the Continental Divide. The cold, stable releases below Dillon Dam created the tailwater conditions that Colorado Parks and Wildlife recognized in 1998 with a Gold Medal Trout Water designation, and that reach — flowing through White River National Forest — now sustains a brown trout fishery capable of producing fish over ten pounds. Paddlers find Class I–II water from Breckenridge down through the Gold Medal tailwater before the river steepens to Class II–III in the lower canyon between Green Mountain Reservoir and the confluence with the Colorado River at Kremmling.