The Bitterroot River is a northward flowing river running through the Bitterroot Valley, from the confluence of its West and East forks near Conner in southern Ravalli County to its confluence with the Clark Fork River near Missoula in Missoula County, in western Montana. The Clark Fork River is tributary to the Columbia River and ultimately, the Pacific Ocean. The Bitterroot River is a Blue Ribbon trout fishery with a healthy population of native westslope cutthroat trout and bull trout. It is the third most fly fished river in Montana behind the Madison and Big Horn Rivers. History The Bitterroot River is named for the bitterroot plant Lewisia rediviva, whose fleshy taproot was an important food source for Native Americans. The Salish called the river Spet-lum for "Place of the bitterroot" and In-shi-ttogh-tae-tkhu for "Willow River". French trappers knew the plant as racine amère (bitter root). The early Jesuit priest, Father De Smet, named it St. Mary's River. By the time of Washington Territory surveys by Governor Isaac I. Stevens in 1853, the name had been translated to Bitterroot River. Watershed The Bitterroot River watershed drains in Ravalli and Missoula counties. The Bitterroot Valley averages 7–10 miles wide and is uniquely low gradient for western Montana streams. The river mainstem begins at the confluence of the East Fork Bitterroot River and the West Fork Bitterroot River. From there the mainstem receives numerous tributaries from the Bitterroot Mountains to the west and the Sapphire Mountains to the east. The watershed is a snowmelt dominated system with large interannual variations in streamflow and peak flows from mid-May to mid-June. The variation is compounded by extensive irrigation withdrawals and upstream reservoir storage at Painted Rocks Reservoir on the West Fork Bitterroot River with the most severely dewatered reaches along of the river located between Woodside Crossing near Corvallis and Bell Crossing near Stevensville. Major tributaries include Skalkaho Creek, and Lolo Creek. The Skalkaho Creek drainage subwatershed originates in the Sapphire Mountains and drains and flows west-northwest to it confluence with the Bitterroot River. Lolo Creek is the primary tributary in the northern portion of the Bitterroot watershed. Lolo Creek is often completely dewatered in late summer in its lower due to withdrawals for irrigation and rural water use. Habitat and wildlife Although the Bitterroot River passes close by to many residential areas, it is an excellent place for wildlife viewing. Many species of