for irrigation. Major cities along the river include Jackson in Wyoming, Twin Falls, Idaho Falls, Boise, and Lewiston in Idaho, and the Tri-Cities in Washington (Kennewick, Pasco and Richland). There are fifteen dams in total along the Snake River, which aside from irrigation, also produce electricity, maintain a navigation channel along part of the river's route, and provide flood control. However, fish passage is limited to the stretch below Hells Canyon. The Snake River watershed is bounded by several other major North American watersheds, which drain both to the Atlantic or the Pacific, or into endorheic basins. On the southwest side, a divide separates the Snake watershed from Oregon's Harney Basin, which is endorheic. On the south, the Snake watershed borders that of the Humboldt River in Nevada, and the watershed of the Great Salt Lake (the Bear, Jordan and Weber rivers) on the south. The Snake River also shares a boundary with the Green River to the southeast; the Green River drains parts of Wyoming and Utah and is the largest tributary of the Colorado River. On the western extremity, for a short stretch, the Continental Divide separates the Snake watershed from the Bighorn River, a tributary of the Yellowstone River, which the Snake begins near. On the north the Snake River watershed is bounded by the Red Rock River, a tributary of the Beaverhead River, which flows into the Jefferson River and into the Missouri River, part of the Gulf of Mexico drainage basin. The rest of the Snake River watershed borders on several other major Columbia River tributaries - mostly the Spokane River to the north, but also Clark Fork in Montana to the northeast and the John Day River to the west. Of these, the Clark Fork (via the Pend Oreille River) and the Spokane join the Columbia above the Snake, while the John Day joins downstream of the Snake, in the Columbia River Gorge. It is of note that the northeastern divide of the Snake River watershed forms the Idaho-Montana boundary, so the Snake River watershed does not extend into Montana. Mountain ranges in the Snake watershed include the Teton Range, Bitterroot Range, Clearwater Mountains, Seven Devils Mountains, and the extreme northwestern end of the Wind River Range. Grand Teton is the highest point in the Snake River watershed, reaching in elevation. The elevation of the Snake River is when it joins the Columbia River.