The Payette River, a major tributary of the Snake River that drains about 3,200 square miles, has long shaped the economy and environment of its basin. Dams and reservoirs on the Payette and its tributaries store water, regulate flows, and generate electricity, but they also have altered the river's ecosystem by replacing extreme flows, flushing, and flooding with regulated flows and more static environments, causing rapid reservoir fluctuations, muddy shoreline areas, increased algae and sediment buildup, changes in water temperature and quality, and blocked fish passage. These changes have been especially severe for anadromous fish such as salmon, which once migrated from the Pacific Ocean to spawning beds high in the basin and are now extinct within the Payette River drainage. The river also figured in the history of Boise Basin mining: after George Grimes discovered gold there in 1862, miners increasingly turned to dredging, which required electricity. The first dredge in Boise Basin was built about 1898, and dredges operated until the 1950s. The first Grimes Pass Dam was built here in 1904, washed away in 1905, rebuilt in 1907 by dredge owner W.H. Estabrook with a power line serving nearby mining towns, and washed out again in 1943; today the South Fork Payette River flows free from its headwaters in the Sawtooth Mountains to its confluence with the North Fork near Banks. Boise Basin was one of Idaho's largest gold rushes, with Idaho City growing to nearly 6,300 people and by 1865 surpassing all other Pacific Northwest cities in size, before many miners left by 1870 for other fields in Idaho, Montana, and Nevada. In the present, the river system remains economically vital: reservoirs including Black Canyon, Deadwood, and Cascade support irrigation for over 155,000 acres of crops in southwest Idaho and eastern Oregon, help generate over 20,000 kilowatts of electricity, and support recreation and tourism through fishing, floating, and whitewater use. Managing the Payette River system remains a balancing act among ecosystem health and the needs of local, regional, and national users, while minimum flows and pools are maintained to support water quality, fish habitat, and wildlife including bald eagles and osprey.