Upper Yellowstone River

The Yellowstone River holds an honored place in the nation’s history. It carries the name of our first national park. William Clark reunited with Meriwether Lewis near the confluence of the Yellowstone and Missouri Rivers following their separate explorations.

The Yellowstone and the Tongue River, its major tributary, are spawning grounds for endangered pallid sturgeon and oddly prehistoric-looking paddle fish. It’s also a vital artery for wildlife and farmers in a harshly arid country and a major source of recreation for millions. As with so many rivers, the Yellowstone is serving a lot of masters – so many that it’s considered among the most threatened rivers in the country.


At different spots along its course, the river faces different threats. Development and channel modification, too much water diverted for irrigation, poor grazing along its banks and invasions of noxious weeds are all threats at different points.

The Yellowstone has been spared the major dams that have stalled so many great rivers. But it is not entirely unobstructed – especially on its major tributaries such as the Tongue. In-channel diversions for irrigation don’t entirely stop flows, but they can be impossible for fish to get past. Similarly, armoring of streambanks have hemmed in the river to a narrow channel in places, curtailing meanders and preventing the Yellowstone from flowing into its natural floodplain. 

Goals & Strategy

The Nature Conservancy is working collaboratively with the many stakeholders that claim this river. The goal is to remove the obstacles to fish movement and free flow of the river while still allowing use of the river for irrigation and other human needs. 

This approach has resulted in either the removal of obstacles or construction of by-passes that have re-opened more than 100 miles of river to fish passage. Innovative channel migration easements are rewilding the river by preventing armoring of banks and other modifications that inhibit natural meanders and seasonal flooding. The Conservancy is working with the Yellowstone River Conservation District Council, several state and federal agencies, agricultural landowners, recreationists, industry, business, environmentalists and local government to continue to open and improve this river system for both fish and people. 


Watch a Slide Show

See the beauty of the Yellowstone, from its rocky cliffs, to its smallest creatures.