Decision Point at the Marias

It was here in 1805 at the junction of the Marias River and the Missouri River, referred to by historians and the like as "Decision Point", that Lewis and Clark were faced with the problem of determining which waterway they should pursue. Their intent was to stay on the river, which the Hidatsa had told them contained some "great falls". It would carry them westward to the Pacific. The captains were puzzled with the fact that the Indians had made no reference to another river. Since they were seeking the best possible route to transverse the continent it was important that they follow the Missouri.

As Lewis wrote, " To ascend [the wrong] stream would not only lose us the whole season, but would probably so dishearten the party that it might defeat the expedition altogether."

Two parties were sent to search for the river that contained the "falls". This would be the course that the Indians had spoken of.

Meriwether Lewis and five other men explored the north fork. William Clark with five men explored the south fork. After several days of scouting the following conclusions were drawn: the north fork of the river was muddy, just as the Missouri had been throughout their journey. This is why most corps members thought it was the correct one to follow. But the captains thought the river should be getting clearer since it was coming out of the mountains and would lead them to the Northwest Passage. Together with what they already knew about river hydrology and geography the captains believed the south fork to be the correct choice.

As it turned out the captains had made the right decision. After ten days the expedition arrived at the "great falls" on the Missouri River where present day Great Falls, Montana is located. The north fork was named the Marias in honor of Lewis' cousin Miss Maria Wood from Virginia.

Two settlements that sprang up near "Decision Point" were Loma and Fort Benton. Both these communities still exist today.