The Gates of the Rocky Mountains


Captain Lewis wrote on July 19, 1805, ” … this evening we entered much the most remarkable clifts that we have yet seen. these clifts rise from the waters edge on either side perpendicularly to the height of 1200 feet. … the river appears to have forced its way through this immense body of solid rock for the distance of 5-3/4 Miles … I called it the gates of the rocky mountains.

Of all of the natural spectacles that Montana might have to offer, I think that the Gates of the Mountains on the Missouri River is probably one of the best. Captain Lewis wasn’t kidding when he described the canyon in his journal — It looks as if the river just “forced” it’s way through the rock.


The boat tours through the gates have been going on for years. There have been millions of people since the times of Captain Lewis that have gazed up at the “most remarkable clifts“, and I’m pretty sure that over the future course of time there will be even millions more that will experience the Gates of the Rocky Mountains.

Gates of the Rocky Mountains rocky outcrops
Gates of the Rocky Mountains rocky outcrops

The day we experienced the gates was not too hot and not too cold. There was a slight breeze over the calm water and the clouds above just came and went at their leisure. There were plenty of boaters and folks fishing and camping along the way.

One of the things I was most interested in was the rock formations. I’ve always been interested in how Montana was made geologically, so I paid extra attention to how the river might have been able to make it’s way through the mountains. When I looked at the sharp rock cliffs, and of how the rock appeared to be folded in various places, I came away with the notion that the mountains might have given way to the river. I didn’t see the tell-tale cutting pattern of direct erosion like I saw on the Colorado River in the Grand Canyon. It appeared to me that some certain geological forces might have opened up a way for the river to pass through without the river having to put up much of an effort.

Gates of the Rocky Mountains cliffs
Gates of the Rocky Mountains cliffs

Captain Lewis had mentioned the “many springs” that were present coming out of the rock (I’m guessing at the water level he was at before the Holter dam was built) as he passed through and to me that might suggest that as the continent was moving westward, water was trapped in the area that might have undermined the base of the mountains in this particular area and caused a weak spot that opened up a way for the river to pass through without having to start the erosion at the surface like the Colorado River had done.

When I hear of the underground Madison River in the area of Great Falls, it’s not that much more of a leap to consider just how much water might be trapped all along the eastern side of the Continental Divide as a result of the North American tectonic plate movement ever grinding toward the west.

Gates of the Rocky Mountains sheer cliff
Gates of the Rocky Mountains sheer cliff

The boat tour through the gates was two hours well spent as far as I’m concerned. I didn’t get to see any Bears or Big Horn Sheep, but I did happen to see the Eagles and the Peregrine Falcons aloft. The canyon cliffs were the headliner however, with the wildlife being the added bonus … at least for me.

The only thing I might regret about our most recent tour of the gates, was the the fact that I didn’t bring the right camera. I’m thinking that next time I’ll bring the same camera that I used at the Petrified Forest National Park and at the Grand Canyon. The Gates of the Rocky Mountains deserve to have great photos taken of it because it’s imposing beauty is very difficult to put into words.

Schedule your own tour

For over 125 years guests have been following in the path of Lewis and Clark exploring the “Gates of the Mountains”. Today the marina and boat tour is operated by the Gates of the Mountains Inc, whose goal is to protect, educate, and allow visitors to explore one of the last best places.

Contacting the Gates

Phone: (406) 458-5241
Office: 9:00 AM – 5:00 PM



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