July 4: Hell's Gate

Ambush Alley

View west

Hell's Gate: a river winding through a constriction in the hills

© 2003 Airphoto, Jim Wark. All rights reserved.

Confluence, Blackfoot and Clark's Fork Rivers, 1863

Cantonment Wright
Capt. Mullan's Winter Quarters in 1861-62
by Gustav Sohon

Sohon historic painting of the Blackfoot river dammed and iced over

Special Collections, Mansfield Library, The University of Montana, Missoula

At the bottom of this photo the Blackfoot River (right) slips under Interstate 90 and contributes its waters—on this day slightly muddy with spring runoff from the mountain snows on the Continental Divide—to the "East fork of Clark's river" (now called the Clark Fork of the Columbia). After tumbling over a hundred-year-old dam the river tests the resistance of a mountain spur known as Mount Jumbo (photo center), then squeezes through the "narrow confined pass" known as Hellgate Canyon–"port d'enfer," as French-Canadian traders called it, because of its notoriety as a place where the "Pahkees"–Shoshone for "enemies" frequently ambushed Shoshone, Salish, and Nez Perce hunting parties bound for buffalo country.

In the photo above, the uneven light lines on the mountainside at left are narrow gravel roads that were built for trucks to haul logs to a lumber mill. The forests here have been thinned by loggers several times since the late 19th century.

Beyond Hell's Gate the Clark Fork arches toward the southwest across the "valley plain," as Lewis called it, to join the Bitterroot River among the cottonwoods at extreme upper left. Lewis and Clark regarded the Bitterroot as the main stem of "Clark's River," and so-named it. By the middle of the 19th century further exploration determined that Lewis's "East Fork of Clark's River" (see Figure 1) was actually the main stem, being 30 miles longer than either the Bitterroot or the Big Blackfoot.

French-Canadian fur trappers and traders passing through the valley around 1850 called it Hell Gate Ronde–rond is a French word for a broad level valley hemmed in by mountains, commonly called a "hole" by contemporary Americans.

The first highway through Hell Gate Ronde was a federal wagon road built in 1858-62 to facilitate communication, troop movements, and general travel between Walla Walla, the easternmost trading post west of the Rockies, and Fort Benton, the head of navigation on the Missouri. The 633-mile route was designated Mullan's Road, after Captain John Mullan, the topographical engineer who surveyed and engineered it, and supervised its construction. Gustav Sohon (1825-1903) was Mullan's interpreter, guide, artist, and illustrator.

Sohon recorded the scene at the meeting of the Big Blackfoot River (left) and the upper Clark's Fork of the Columbia (right) at the beginning of the coldest winter the local Indians could remember. The Blackfoot was completely frozen over, the Clark's Fork fringed by thick ice. First, the men built several log huts, which Mullan named Cantonment Wright after his commanding officer, George Wright. The river ice, soon thick enough to support horses, enabled the sinking of stone piers to support a four-span, 235-foot wagon bridge–the first in the far West. The bridge was completed by the first of March, well before the next spring freshet began to rise.1 In the years following, it was frequently damaged by spring floods, and as a result its utility was relatively short-lived. Meanwhile, Indian people in the region must have looked upon it as an amazing leap in transportation, compared with their ages-old modes of crossing rivers.


The first settlement in Hell Gate Ronde–now known as the Missoula Valley–began in 1860 on Mullan's Road in the vicinity of Lewis's creekside campsite of July 3, 1806. In 1864 Hellgate Village moved a few miles up the Clark Fork, encouraged by the influx of travelers headed for the gold fields around Willard's Creek over in the Big Hole. The new location centered on two mills built to satisfy the immediate needs of any prospective town–in those days, lumber and grain. Its new name was Missoula, a corruption of the Salish Indian placename phonetically written Nemissoolatakoo, and meaning "place of rushing waters."

Restoring a River

Lewis described water of the "East fork" and the Cokahlahishkit–the "river of the road to the buffaloe"–as "terbid but the East branch much the most so; their beds are composed of sand and gravel; the East fork [Clark's Fork] possesses a large portion of the former" (and the slipperiest round rocks that ever dunked a fly fisherman). Neither was navigable, he added, "in consequence of the rapids and shoals which obstruct their currents." One of those rapids formed the foundation for the 21-foot-high dam, completed in 1908 and known as the Milltown Dam, Milltown being a long-time lumber processing center for the logging industry in the Blackfoot River drainage.

During the past century the Milltown Dam has impounded 6.6 million cubic yards of upstream sediment, including about 2 million yards of heavy metals–arsenic, copper, zinc, iron, and manganese–from the mines and smelters of Butte and Anaconda, on the west slope of the Continental Divide, 125 river miles to the east. In 1982 sanitation engineers, responding to complaints from local residents, found arsenic in the drinking water of Milltown, the small community at lower right in the above photo. Soon a coalition of concerned citizens and local officials set in motion an intense effort to remove the antiquated dam, haul away the contaminated sediment behind it, and not only improve the quality of the aquifer but also restore the endangered bull trout to their native habitats in the Big Blackfoot and upper Clark Fork Rivers.

Excellent Road

In an undated document, Clark reported: "The Indians inform us that there is an excellent road from the 3 forks of the Missouri through a low gap in the mountains to the East fork of Clarks river which passes down that fork to its junction and up on the West Side of the main fork to Travellers rest Creek which they travel with their families in 6 days."2 Having observed that Indian bands generally travelled about 25 miles per day, he estimated the distance to be about 150 miles.3. The highways that today parallel those ancient Indian trails from Three Forks to the present Travelers' Rest State Park via Clark's "low gap in the mountains," cover about 185 miles (218 Km), which can be driven in three hours at the posted speeds.

John Mix Stanley's View (1854)

Looking east

Stanley, Hell Gate: Historic painting of a river exiting a canyon into a round valley

John Mix Stanley (1854)

John Mix Stanley, one of the two artists (the other was Gustav Sohon) who were members of Isaac Stevens' expedition to find a potential railroad route to the Pacific,3 here presents a view of Hell's Gate, once known by the French equivalent Port d'Enfer, looking east from from Hell Gate Ronde. The French word "ronde" in this context is synonymous with the English word "hole" as applied to a broad, flat valley hemmed in by mountains. The French names for this place were dropped well before the close of the 19th century. In reality, the sharp peak at right, now called Mount Sentinel, is not that sharp, and the mountain to the left of the canyon, long known as Mount Jumbo, is lower and less rugged than Stanley shows it. Mount Sentinel and the adjoining mountains constitute the northern terminus of the Sapphire Range; Mount Jumbo is the south end of the Rattlesnake Mountains, which are extensions of the Mission Range.

Cadotte's Pass got its name from Jean-Baptiste Cadotte, a French-Canadian trapper and interpreter who was a partner of fur trader Alexander Henry the Elder (1739-1834). This gap is three and one-half miles south-southeast of the one Lewis crossed, and two miles north-northwest of Rogers Pass, where U.S. Highway 200 goes over the Continental Divide. All three passes are roughly 100 miles from Hell Gate canyon. Thus Stanley's title for his painting reflects the Stevens party's decision that Cadotte's Pass would be the preferred route for a railroad through this part of the Rockies. Ultimately, the Northern Pacific Railway, which was completed in 1883, followed the Indian Road along the "East Fork of Clark's River" after crossing the Divide at Homestake Pass. All three gaps are somewhat over 6,000 feet in elevation.

Indeed, in terms of scenic grandeur, the mountains like these that surround the Clark Fork Valley do not fit the image most people have in mind for "real mountains." They don't display the magnificence of Glacier National Park, the Grand Tetons, or the craggiest summits in Colorado or Canada. The many ranges that make up the Rockies between the 45th and 48th parallels are not as high as those others, but they're just as steep, overall, and that's what counts, and the rivers and streams that drain them and separate them have served to define the practical travel routes that penetrate them.


1. United States Army, Corps of Topographical Engineers, Report on the construction of a military road from Fort Walla-Walla to Fort Benton, (Washington: Government Printing Office, 1863), 33.

2. Moulton, "Postexpeditionary Miscellany," 8:394.

3. The word "mile" is a Middle English contraction of the Latin expression milia passum, which denoted a thousand double paces.

4. Watercolor paintings by Stanley and Sohon, totalling 70 in all, provided a more extensive visual account of the Northwest than had previously been published. They appeared in Volume 12 of the Narrative and Final Report of Explorations for a Route for a Pacific Railroad near the Forty-Seventh and Forty-Ninth Parallels of North Latitude, from St. Paul to Puget Sound (12 vols. in 13, Washington, D.C.: 1855). The forty-fifth parallel is about 100 miles north of Travelers' Rest; the forty-ninth parallel marks the boundary between the U.S. and Canada in this part of the continent.

Funded in part by a grant from the Montana Cultural Trust