The Watershed

The East Gallatin River and Bridger Mountains. Photo by Chris Boyer,

The East Gallatin River and Bridger Mountains. Photo by Chris Boyer,

The Gallatin Watershed begins in Yellowstone National Park and covers nearly 1.2 million acres in southwest Montana. With spectacular mountain peaks, lush valleys, and arid sagebrush, the watershed’s beauty is in its diversity.

In 1806, the Corps of Discovery, led by Lewis and Clark, marveled the Gallatin River. Lewis named the river after US Treasury Secretary Albert Gallatin.

Even before this, Native Americans—including Blackfeet, Crow, Bannock, Nez Perce, and Shoshone—hunted in the Gallatin Valley.

Today, the Gallatin River is a Blue Ribbon trout stream and has some of the best whitewater in southwest Montana.

The Gallatin and East Gallatin Rivers also irrigate some of the most productive farm fields in the state.

River Systems

Click to enlarge map.

The watershed has 23 major streams totaling 394 miles. The (West) Gallatin River begins in Yellowstone and flows northeast along Highway 191. The East Gallatin River forms from the Gallatin and Bridger Mountains then flows through Bozeman and Belgrade. The West and East Gallatin Rivers merge near Manhattan to form the Gallatin River proper, which joins the Madison and Jefferson Rivers at Three Forks to form the Missouri River.

The Gallatin Watershed is of national significance as the headwaters of the Missouri River. Residents of the Gallatin enjoy the privilege of being the first people to touch this water on its journey to the Gulf of Mexico.



Even as a headwaters watershed, stream health and water quality is a concern. In the Lower Gallatin Watershed, 15 streams do not meet state water quality standards for nutrients, sediment, and/or E. coli.

Additionally, Gallatin County is the fastest growing in Montana. With the conversion of land from agriculture to residential uses and increasing climatic variability including drought, pressure on the water resources of the Gallatin is intensifying. As water quantity and quality issues increase we must carefully plan for the future of our watershed.

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