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Lewis and Clark
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Historic Sites and Buildings

historic site Confluence of the Marias and Missouri

Location: Chouteau County, just off a secondary road leading from U.S. 87, about one-half mile southwest of the village of Loma.

Had Lewis and Clark not made the right decision as to what stream to follow at the juncture of the Marias and Missouri and proceeded up the former, the expedition might have failed. The lost time would have seriously reduced the limited food supply; probably have prevented a crossing of the mountains ahead before winter set in; and might have resulted in a disastrous meeting with hostile Blackfeet, whose homeland was along the Marias.

Well aware of most of the implications of the wrong choice of route, the two captains bivouacked at the rivers' junction from June 2, 1805, until June 11-12. Lewis named the Marias as "Maria's River" after Maria Wood, a cousin in Virginia. At the confluence of the two streams, the commanders were confronted with their first major geographical dilemma. They were particularly puzzled because they had earlier decided that the Milk River was the one flowing in from the north that the Minitaris had described. To determine which of the rivers was the Missouri, the route to the Rockies and the Shoshonis, the cautious leaders with small parties separately reconnoitered a considerable distance up each stream.

Most of the command believed the Missouri was the northwestern fork, which was muddy like the Missouri so far and discharged an almost equal volume of water. Lewis and Clark, in a fine example of geographic insight and analysis, decided the Missouri was the somewhat larger southwestern fork. It flowed from the expected direction and possessed the characteristics of a stream originating in nearby mountains: swift current, clear water, and a rocky bed.

Knowing that the Great Falls of the Missouri would be not far ahead if their decision was correct, on July 11 Lewis and four men moved ahead overland to find them. The next day, Clark and the boat party followed. Left behind was the red pirogue, which was hidden on a small island at the mouth of the Marias. Some supplies were also cached along the riverbank.

On the eastbound trip, the Lewis contingent of the expedition, consisting of the commander, Sergeants Gass and Ordway, and 17 enlisted men, spent only part of a day, July 28, 1806, at the juncture of the Marias and Missouri. Fearing an encounter with Blackfeet, the party hurriedly recovered the cache but left the badly decayed red pirogue and four horses. The group then headed downriver in five canoes and the white pirogue to reunite with the Clark element.

Since 1805-6, the junction of the Marias and Missouri has changed several times and is now impossible to locate as it was in the days of Lewis and Clark except in a general way. At that time, it was probably about 2-1/2 miles downstream from the present confluence. The bluffs and bottom lands of both rivers define the limits within which the two streams might then have strayed. The bluff lines of both of them are now high and well defined; the country back from their channels is rough where the drainage cuts down to them from the upland plains. One of the more recent superseded channels of the Marias now is a dry bed running nearly parallel to the Missouri for 2-3 miles and finally angling into it in a willow and cottonwood thicket. Even today, the surrounding land, a rough, brown, almost treeless expanse, is little changed from the Lewis and Clark era except for the village of Loma. It is almost lost to view in the cottonwood and willow bottom near the mouth of the Marias. Most of the land in the vicinity is privately owned.

Last Updated: 22-Feb-2004