Montana's Greatest Wonder: The Missouri River (Part 1 of 5)

Photo: The Madison River flows past autumn foliage upstream from Ennis. (Photo by Rick and Susie Graetz)

Photo: The Madison River flows past autumn foliage upstream from Ennis. (Photo by Rick and Susie Graetz)

On Aug. 12, 1805, Meriwether Lewis penned in his journals, “the road was still plain, I therefore did not dispare of shortly finding a passage over the mountains and of tasting the waters of the great Columbia this evening. At the distance of four miles further the road took us to the most distant fountain of the waters of the mighty Missouri in search of which we have spent so many toilsome days in wristless nights.” Lewis was describing today’s Distant Fountain Spring, part of Trail Creek, flowing from the east side of the Continental Divide at Lemhi Pass. Climbing above the trickle, Lewis became the first known white man to have stepped onto and across the Continental Divide.

However, in terms of the most distant waters, he was a bit off. That honor is reserved for a spring and Hellroaring Creek, which comes off the Montana side of the Continental Divide just below 9,846-foot Mount Jefferson at the extreme eastern end of the Centennial Range, west of Yellowstone National Park. Hellroaring has a short life. It is hastily consumed by Red Rock Creek, which begins just off the Divide below Red Rock Mountain at Lillian Lake, 9,000 feet above sea level, near Red Rock Lakes National Wildlife Refuge.

Standing at Three Forks, the headwaters of the Missouri, on July 28, 1805, Lewis wrote, “Both Capt. C. and myself corrisponded in opinion, with rispect, to the impropriety of calling either of these streams the Missouri and accordingly agreed to name them. we called the S.W. Fork, that which we meant to ascend, Jefferson’s river in honor of Thomas Jefferson. the Middle fork we called Madison’s River in honor of James Madison, and the S.E. Fork Gallitian’s river in honor of Albert Gallitian.” For whatever reason, Albert’s name was corrupted to Gallatin.

At this point, the three tributaries make their presence well known. The Madison and Jefferson, each close to 100 feet wide, join and cover a short distance before meeting the equally broad Gallatin. Of all three tributaries, the Jefferson, counting its suppliers, drains the largest area and the Gallatin the smallest.

Hellroaring and Red Rock creeks are the Jefferson’s source. Red Rock River falls out of the mountains and courses through a most beautiful setting, the Centennial Valley and the Red Rock Lakes National Wildlife Refuge. Slowing to fill Upper and Lower Red Rock lakes, it offers haven and nesting ground for species such as the trumpeter swan. At the western end of the valley, the river enters 13-mile-long Lima Reservoir. Until this point, the river expanded westward. Beyond the man-made lake, it continues northwesterly until it meets Clark Canyon Reservoir and the waters of Horse Prairie Creek, entering from the west. “The Most Distant Fountain Spring” as labeled by Lewis, and Trail Creek, are at the upper end of Horse Prairie.

In the Corps of Discovery’s time, Red Rock River and Horse Prairie Creek coupled in an area the captains christened “Shoshone Cove near their Camp Fortunate (now buried by the waters of Clark Canyon Reservoir). From this point north to the Three Forks, the explorers called the entire stream “Jefferson’s river.” Today, where the creek and river convene somewhere under the reservoir, the Beaverhead River is born and flows forth, switching in and out of narrow canyons and wide valleys before partnering with the Ruby River. A short ways beyond the town of Twin Bridges it meets the Big Hole River. It is from this point that the present Jefferson River runs to the Three Forks.

The Madison River gains its foothold where the Gibbon and Firehole rivers meet in western Yellowstone National Park. The Firehole begins on the Madison Plateau and Continental Divide just south of Old Faithful near Shoshone Lake. During its journey to meet the Gibbon River at the Park’s Madison Junction, it runs north through three geyser basins.

The Grebe Lake area, northwest of the Grand Canyon of the Yellowstone, gives the Gibbon its start. From here it travels west, taking in two geyser basins, several rapids and an 84-foot plunge over Gibbon Falls before joining the Firehole at Yellowstone’s Madison Junction.

From this confluence, the newly made Madison, heading west to northwest, passes herds of bison and elk before leaving the park. It takes a brief rest in Hebgen and Quake lakes (site of a major earthquake in 1959) before rushing full of life into the spacious Madison Valley, where it holds court as one of Montana’s premiere fly-fishing destinations. Moving north, between the Madison and Gravelly mountain ranges, it spreads out in Ennis Lake, then squeezes into Bear Trap Canyon on its way to the Gallatin Valley and its destiny to begin the Missouri.

In the northwest corner of Yellowstone National Park, Three Rivers Peak and Gallatin Lake send off the Gallatin River. It tumbles through a beautiful valley, then eases into Gallatin River Meadows – a favorite for backcountry skiers – before leaving the park and wedging itself into the constricted and magnificent Gallatin River Canyon, formed by steep rises of the Gallatin Range looking down from the east and the Madison Range across the way. The abrupt demise of the canyon southwest of Bozeman allows the river to spill into the ample and fertile Gallatin Valley and on to Three Forks.

A hallmark of southwest Montana is its grand valleys – sage-filled bottomlands surrounded by distant high peaks. The Madison, Gallatin and Jefferson rivers traverse such country.

Rick & Susie Graetz
University of Montana
Department of Geography