The Spokane River drains the northern part of Lake Coeur d'Alene in the Idaho Panhandle, emptying into the Columbia River at Franklin D. Roosevelt Lake, approximately 180 km downstream. From Lake Coeur d'Alene, the Spokane River traverses the Rathdrum Prairie until reaching Post Falls, Idaho where it passes over a dam, and a natural 40-foot waterfall. Continuing westward it passes over 6 more dams, three of which are located in the city of Spokane. In Spokane, it flows over the Spokane Falls, which are located in the heart of Downtown Spokane, approximately one third of the way down the river's length. About a mile later, the river receives Latah Creek from the southeast. Soon afterwards, it is met from the northeast by the Little Spokane River, on the western edge of the city of Spokane. It flows in a zigzag course along the southern edge of the Selkirk Mountains, forming the southern boundary of the Spokane Indian Reservation, where it is impounded by the Long Lake Dam to form Long Lake, a 15 mi reservoir. It joins Franklin D. Roosevelt Lake on the Columbia from the east at Miles. The site of historic Fort Spokane is located at the confluence of the Spokane and Columbia rivers. The Spokane River's entire drainage basin is about large, of which are above Post Falls Dam at the outlet of Coeur d'Alene Lake. Its mean annual discharge is.
Human use
Until the 18th century, the Coeur d'Alene and Spokane Native Americans used to live and travel along the banks of the Spokane River. In 1807, David Thompson was the first European to cross the Rocky Mountains and explore the area. Today, the metropolitan area of the city of Spokane, Washington is the largest human settlement on the banks of the Spokane River. The metropolitan areas of Coeur d'Alene and Post Falls, Idaho are also seated alongside the river. The Spokane River and Lake Coeur d'Alene are the primary sources of recharge for the Spokane Valley–Rathdrum Prairie Aquifer, which is the primary source of drinking water for each of these settlements.
After the Northern Pacific Railway lines arrived in Spokane in 1882, there was rapid growth in milling operations along the river. Many of these mills required dams to provide power for their machinery. As a result of the dams blocking the river, salmon populations in the Spokane plummeted, leading to complaints from many of the people living upstream. After the construction of Little Falls Dam in 1910 by Washington Water Power blocked upstream passage, the river's salmon populations disappeared completely. Steelhead were also abundant on the Spokane River, prior to pollution and the construction of the dams. Today, the Spokane River system is one of the two largest unoccupied stretches of steelhead habitat within their former range. Today, the Spokane River supports populations of rainbow trout, northern pikeminnow, and Bridgelip Suckers, as well as several non-native species. Many of the remaining fish, however, are not suitable for human consumption due to the chemical pollution in the river, with signs alongside the river warning that the fish are contaminated with PCBs.
