The Missouri and the Milk

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"Loney always wondered how that river knew
where to bend, why it wandered with such
feckless purpose. He wondered if it always
sought the lowest ground, or was his mind
such a shambles that he assumed there was
a reason behind its constant shifting?"

Milk and Missouri River Confluence

A small, crooked, and muddy river entering the blue Missouri River

© 2000 Jim Wark, Airphoto

Millions of years ago the valley of the river Lewis and Clark named Milk was part of the main channel of the Missouri. In this photo, taken a month or so later than the one below, it writhes through its ancient bed, a pitiful trickle of its original self, still contributing its rich murk to "The Big Muddy."

A small, crooked, and muddy river entering the blue Missouri River

© 2000 Jim Wark, Airphoto

The confluence of the Milk River (left) and the Missouri, looking downstream (eastward). Note the parallel rows of Cottonwood trees marking the various historic margins of spring freshets. At right are fringes of the Milk River Hills.

The Hidatsa Indians had told the captains to watch for it. "About one hundred fifty miles on a direct line, a little to the N. of West [from the mouth of the Yellowstone], a river falls in on the N. side called by the Minetares [Hidatsas] Ah-mâh-tâh, ru-shush-sher or the river which scolds at all others."2

This river they state to be of considerable size, and from it's position and the direction which they give it, we believe it to be the channel through which those small streams on the E side of the Rocky Mountain, laid down by Mr. Fidler3, pas to the Missouri. It takes it's source in the Rocky mountains S. of the waters of the Askow or bad river, and passes through a broken country in which there is a mixture of woodlands and praries.

They arrived at its mouth on May 8, 1805, and stopped "in a handsome bottom" for lunch:

I took the advantage of this leasure moment and examined the river about 3 miles; I found it generally 150 yards wide, and in some places 200. it is deep, gentle in it's courant, and affords a large boddy of water; it's banks, which are formed of a dark rich loam and blue clay, are abbrupt and about 12 feet high. it's bed is principally mud. I have no doubt but it is navigable for boats perogues and canoes, for the latter probably a great distance. the bottoms of this stream are wide, level, fertile and possess a considerable proportion of timber, principally Cottonwood. from the quantity of water furnised by this river it must water a large extent of country; perhaps this river also might furnish a practicable and advantageous communication with the Saskashiwan river; it is sufficiently large to justify a belief that it might reach to that river if it's direction be such.

Lewis was particularly impressed by the color of this stream the Hidatsas explained was the principal northern source of the Missouri. "The water of this river," he wrote, "possesses a peculiar whiteness, being about the colour of a cup of tea with the admixture of a tablespoonfull of milk." Clark concurred: "It precisely resembles tea with a considerable mixture of milk." From the color of its water, Lewis concluded, "we called it Milk river." Patrick Gass, with different eyes, or imperfect recollection, remarked that "there is a good deal of water in this river which is clear." We may suppose that it was not as milky as it appears in Jim Wark's photo, above, which may reflect a recent, heavy rain. In any case, the reason for its hue is that it drains a broad valley containing weathered, silty glacial till and shale, as well as sand, and passes through a layer of white clay within its middle reaches.

Returning downriver in 1806, Lewis paused for a few minutes at the mouth of the Milk again on August fourth. "This stream is full at present, and its water is much the color of that of the Missouri. It affords as much water at present as Maria's river, and I have no doubt extends itself to a considerable distance North." Gass, too, noted that it "was very high and the current strong."

Needless to say, Lewis, having recently been disappointed to discover the Marias didn't satisfy his objectives, was still hoping that the Milk River drainage would define the northern boundary of Louisiana Territory near the South Saskatchewan River, or at least a little north of the 50th parallel. He would have been disappointed, for its northern tributaries begin at no more than about 49° 14' North Latitude.

They looked it over carefully, as far as they could see. Clark climbed to "a very high point opposite to the mouth of this river"—probably today's Deadman Butte, in the Milk River Hills. Lewis learned from him that he had enjoyed "a perfect view of this river and the country through which it passed for a great distance. . . . Capt C. could not be certain but thought he saw the smoke [from] some Indian lodges at a considrable distance up Milk river." Lewis stiffened, groped for a respectful euphemism, and settled on the one he used for grizzly bears and wolves. "We do not wish to see those gentlemen just now as we presume they would most probably be the Assinniboins and might be troublesome to us."

The Milk River begins 732 miles (1,178.5 km) west of its confluence with the Missouri, in the shadow of the Rocky Mountain Front, on the Blackfeet Indian Reservation near Glacier National Park.4 Since 1921, with the help of human engineering, it has drawn part of its water from the park's large Lake Sherbourne, which nature originally designed to empty into Hudson's Bay via the Belly River. The objective was to provide a backup source of water to supply the elaborate irrigation system during dry late summer months.5 The Milk flows northeast across the International Boundary south of Lethbridge, Alberta, and returns to Montana 200 miles downstream, northwest of Havre (HAVE-er). A short distance upstream from Havre, Fresno Dam impounds a reservoir from which irrigation water is distributed to 120,000 acres of alfalfa, wheat, barley, and other crops along the Lower Milk River.


1. New York: Harper & Row (1979), p. 113.

2. Unfortunately, neither the Hidatsas nor the captains left any clues as to the reason behind that enigmatic name. The copyist who first edited Joseph Whitehouse's journal, inserting his personal guesswork, transcribed it as "Scalding Milk River."

3. Peter Fidler (1769–1822) was a surveyor for the Hudson's Bay Company who copied a sketch-map given him by a Blackfeet Indian informant named Ackomokki. It was pure hearsay in its representation of the Northern Rockies and their drainages, since Fidler himself did not travel south of the fiftieth parallel until he visited the Knife River villages in 1813, Aaron Arrowsmith,however, whose state-of-the-art map Lewis and Clark carried, relied upon it heavily. See John Logan Allen, Lewis and Clark and the Image of the American Northwest (New York: Dover, 1975), pp. 244–45.

4. River Mile Index of the Missouri River (Water Resources Division, Montana Department of Natural Resources and Conservation, 1979), p. 29.

5. The Milk River Project of the U.S Department of the Interior, Bureau of Reclamation, was initiated in 1902, followed by forty-two years of development. A detailed description and history of the project is available at ( Accessed January 28, 2008).