# What did Lewis and Clark imagine a Missouri-river Northwest Passage would look like? **URL:** \ **Category:** Factual Questions\ **Created:** [June 22, 2024, 2:27pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200 "2024-06-22T14:27:32Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![toadspittle](https://avatars.discourse-cdn.com/v4/letter/t/c0e974/32.png) [@toadspittle](https://boards.straightdope.com/u/toadspittle)\ **Post date:** [June 22, 2024, 2:27pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/1 "2024-06-22T14:27:32Z")
I’m rewatching Ken Burns’ Lewis & Clark and am still puzzled by one thing: What did Jefferson, Lewis, Clark, et al imagine a Missouri-river Northwest Passage would look like? Did they hope there was a big lake that fed both the Missouri and a westward-draining counterpart? Had any such geographical passage ever been discovered anywhere else in the world? To my understanding (as a Pennsylvania boy), there isn’t a “Northwest passage” that even connects the Chesapeake and the Mississippi over the comparatively tiny Appalachians. And absent serious portaging, the St. Lawrence wasn’t navigable from the Atlantic to the Great Lakes/Mississippi before modern canals were built. I admire the general spirit of exploration and the need to map out the new purchase, but the idea of the river passage seems … poorly thought-out. ---
**Author:** ![dolphinboy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dolphinboy/32/330_2.png) [@dolphinboy](https://boards.straightdope.com/u/dolphinboy)\ **Post date:** [June 22, 2024, 2:34pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/2 "2024-06-22T14:34:43Z")
I believe they thought it would be a series of navigable lakes and rivers that run East/West across North America from the Atlantic to the Pacific Ocean. Similar to the Great Lakes and the St. Lawrence River, but of course much longer. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [June 22, 2024, 3:10pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/3 "2024-06-22T15:10:05Z")
Why did they think a Northwest Passage existed? Did they hear stories from Spanish or French explorers, or from Native Americans beforehand? ---
**Author:** ![steronz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/steronz/32/11765_2.png) [@steronz](https://boards.straightdope.com/u/steronz)\ **Post date:** [June 22, 2024, 3:20pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/4 "2024-06-22T15:20:14Z")
Even a passage that required some overland traversal would be pretty huge, no? I had to look it up but it seems like Europeans knew very little about the Pacific Northwest at all. The Columbia River wasn’t discovered by Europeans until 1792, a mere 13 years before Lewis and Clark reached it. And none of those explorers in the late 1700s had the capacity to explore much up river. Did anyone know how far the Rocky Mountains even extended when they set out? ---
**Author:** ![snowthx](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/snowthx/32/10660_2.png) [@snowthx](https://boards.straightdope.com/u/snowthx)\ **Post date:** [June 22, 2024, 3:36pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/5 "2024-06-22T15:36:54Z")
Just speculating here, but I doubt anyone thought they’d find an _easily_ navigable route to the Pacific, like they could just have barges pulled up one river and then down the other. I would assume they were thinking a partially navigable river route followed by a few portages over not-overly difficult terrain, to another partially navigable river leading to the Pacific. Perhaps they were considering wagon routes that followed river courses rather than over the mountains as the “Northwest Passage”? I guess they were not expecting the Rockies to be so rocky, or high. At any rate, someone had to go check it out, and I could see them tacking on “…to find the Northwest Passage…” to add more justification for financing the expedition, as opposed to just being a grand camping trip. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [June 22, 2024, 3:44pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/6 "2024-06-22T15:44:38Z")
> [@snowthx](#): > > At any rate, someone had to go check it out, and I could see them tacking on “…to find the Northwest Passage…” to add more justification for financing the expedition, as opposed to just being a grand camping trip. That makes a lot of sense. ---
**Author:** ![Railer13](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/railer13/32/9742_2.png) [@Railer13](https://boards.straightdope.com/u/Railer13)\ **Post date:** [June 22, 2024, 3:54pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/7 "2024-06-22T15:54:11Z")
> [@toadspittle](#): > > the St. Lawrence wasn’t navigable from the Atlantic to the Great Lakes/Mississippi before modern canals were built. Correct, as there was a tiny obstacle called Niagara Falls between Lake Erie and Lake Ontario. But…there was a comparatively easy passage between the Great Lakes and the Mississippi River system. The [Chicago Portage](https://en.wikipedia.org/wiki/Chicago_Portage) was just a six-mile link between the two great waterways. Perhaps L&C hoped to find a similar link. ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [June 22, 2024, 6:57pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/8 "2024-06-22T18:57:10Z")
To be fair, you can get from Pittsburgh, Pennsylvania to Great Forks or Billings, Montana by river: [![](https://upload.wikimedia.org/wikipedia/commons/c/c3/Mississippiriver-new-01.png) ](https://upload.wikimedia.org/wikipedia/commons/c/c3/Mississippiriver-new-01.png) And then you can travel from Missoula, Montana to Astoria, Washington: > **[List of longest rivers of the United States (by main stem)](https://en.wikipedia.org/wiki/List_of_longest_rivers_of_the_United_States_(by_main_stem)#/media/File:Columbiarivermap.png)** > > Download coordinates as: > The longest rivers of the United States include 38 that have main stems of at least 500 miles (800 km) long. The main stem is "the primary downstream segment of a river, as contrasted to its tributaries". The United States Geological Survey (USGS) defines a main-stem segment by listing coordinates for its two end points, called the source and the mouth. Some well-known rivers like the Atchafalaya, Willamette, and Susquehanna are not included in this list because their ... It looks like you might need to perform a small portage in Montana but, if you’re trying to move thousands of pounds of equipment in the pre-railroad age then that would probably be your best route to the West Coast. ---
**Author:** ![Dallas\_Jones](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dallas_jones/32/3277_2.png) [@Dallas\_Jones](https://boards.straightdope.com/u/Dallas_Jones)\ **Post date:** [June 22, 2024, 7:06pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/9 "2024-06-22T19:06:30Z")
It was officially called the Corps of Discovery, commonly refered to as the Lewis and Clark Expedition. They had only limited information about what was out there in the Lousiana Purchase. And water was the easiest way to move people and supples anywhere, at that time. Still is. ---
**Author:** ![K364](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k364/32/5_2.png) [@K364](https://boards.straightdope.com/u/K364)\ **Post date:** [June 22, 2024, 7:39pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/10 "2024-06-22T19:39:55Z")
Yeah, they set off to find out having no real idea. But they were influenced by the (probably apocryphal) account of [Moncacht-Apé](https://en.wikipedia.org/wiki/Moncacht-Ap%C3%A9#Influence_on_later_explorers) who claimed to have traversed between the head-waters of the Missouri and the head-waters of the Columbia. Moncacht-Apé didn’t mention any difficulties crossing the Great Divide. But Lewis and Clark had a bugger of a time and their choice of the [Lemhi Pass](https://en.wikipedia.org/wiki/Lemhi_Pass) turned out to be a poor choice and to this day is not a viable crossing. With 20-20 hindsight they would have had a much easier time if they had taken the Yellowstone river and taken what would become the Oregon Trail. ---
**Author:** ![K364](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/k364/32/5_2.png) [@K364](https://boards.straightdope.com/u/K364)\ **Post date:** [June 22, 2024, 7:58pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/11 "2024-06-22T19:58:05Z")
I should have said between the head-waters of the Missouri and tributaries of the Columbia. The head-waters of the Columbia are in [Canada](https://en.wikipedia.org/wiki/Columbia_Lake) ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [June 22, 2024, 8:12pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/12 "2024-06-22T20:12:06Z")
It was known that the Missouri River trended northwest, but only mountain men and Indians knew much about the Rockies of America. Mackenzie had already reached the west coast in 1789 by following what was eventually named the Mackenzie River in Canada. Jefferson was more interesting in laying claim to all of the Indian Territories than he was in reaching the Pacific, although his charter for Lewis & Clark stated that they were to search for a water route. I suggest reading **Undaunted Courage** by Ambrose if you haven’t already done so. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [June 22, 2024, 8:35pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/13 "2024-06-22T20:35:44Z")
I mean, even without a Northwest Passage, the expedition was still a huge success. I think it quite plausible that the organizers knew about all the other benefits to exploration, and knew or strongly suspected that that would be enough, but threw in the bit about a water route to help sell the idea. And, hey, it could have happened, so might as well add it to the list of what you’re asking the explorers to look for. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [June 22, 2024, 9:31pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/14 "2024-06-22T21:31:29Z")
> [@Sage\_Rat](#): > > To be fair, you can get from Pittsburgh, Pennsylvania to Great Forks or Billings, Montana by river: I assume you mean Great Falls, there. I don’t know if Great Falls was reachable by boats larger than a canoe at the time, but I’d be surprised if it was. > [@](#): > > [https://upload.wikimedia.org/wikipedia/commons/c/c3/Mississippiriver-new-01.png](https://upload.wikimedia.org/wikipedia/commons/c/c3/Mississippiriver-new-01.png) > > And then you can travel from Missoula, Montana to Astoria, Washington: > > [List of longest rivers of the United States (by main stem) - Wikipedia](https://en.wikipedia.org/wiki/List_of_longest_rivers_of_the_United_States_(by_main_stem)#/media/File:Columbiarivermap.png) > > It looks like you might need to perform a small portage in Montana but, if you’re trying to move thousands of pounds of equipment in the pre-railroad age then that would probably be your best route to the West Coast. You mean a not-so-small portage. Great Falls and Missoula are not that close together. Plus there’s a couple mountain ranges in between that would be in that “small portage”. On the Columbia, you’re ignoring that it was not completely navigable even by canoes at the time. Notably, this obstacle: > **[Celilo Falls](https://www.oregonencyclopedia.org/articles/celilo_falls/)** > > Celilo Falls (also known as Horseshoe Falls) was located on the mid-Columbia River about twelve miles east of The Dalles. It was part of an approximately nine-… ---
**Author:** ![Schnitte](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/schnitte/32/9033_2.png) [@Schnitte](https://boards.straightdope.com/u/Schnitte)\ **Post date:** [June 22, 2024, 9:43pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/15 "2024-06-22T21:43:38Z")
> [@toadspittle](#): > > Did they hope there was a big lake that fed both the Missouri and a westward-draining counterpart? Had any such geographical passage ever been discovered anywhere else in the world? [Wollaston Lake](https://en.wikipedia.org/wiki/Wollaston_Lake) in Saskatchewan straddles the continental divide and had already been discovered. I don’t know, however, if this is the kind of thing Lewis and Clark had in mind. ---
**Author:** ![Sage\_Rat](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sage_rat/32/399_2.png) [@Sage\_Rat](https://boards.straightdope.com/u/Sage_Rat)\ **Post date:** [June 22, 2024, 10:04pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/16 "2024-06-22T22:04:21Z")
> [@dtilque](#): > > You mean a not-so-small portage. Great Falls and Missoula are not that close together. I said “a portage in Montana”. I pointed out two general locations in Montana that were identifiable on the map, in the state, that were accessible by river from the East Coast in the state to give **some sense** of how far West you could go but you can clearly see on the map that there’s more river after those two cities and there’s probably a variety of other rivers and streams that aren’t displayed, which is before getting to the question of terrain. > [@](#): > > Plus there’s a couple mountain ranges in between that would be in that “small portage”. Yes, I have no illusion that drawing a straight shot between two locations that we can barely see on two terrain-free maps, showing tens or hundreds of miles as single pixels, is likely to be the best way to choose the best path for transferring goods overland. I pegged “somewhere in Montana” as a plausible place to start looking, and nothing more. It would be reasonable for someone, in the 18th century, to envision that - with work and infrastructure - you might one day be able to create a stable transit route. > [@](#): > > On the Columbia, you’re ignoring that it was not completely navigable even by canoes at the time. Notably, this obstacle: Likewise, I have no illusion that, because it appears on a crazy high level view map from 2024, that 100% of the river was exactly as shown, back in the 18th century, and was some perfect highway for any vessel of any size. I would expect that there would be a mix of improvements that would need to be made by the government and local portages to skip by bad portions. Assuming that the railroad had never been invented, I’d generally expect that you’d slowly move from having something that’s largely infeasible for transportation to the West Coast minus some massive effort by small crews moving smaller loads to - a century or two later - having a well-oiled transportation freeway that included a variety of ramps, canals, water elevators, and etc. which could move bulk goods all of the way from one ocean to the other. Not having everything handed to you doesn’t mean that there’s no hope ever of achieving some reasonable goals. ---
**Author:** ![enipla](https://avatars.discourse-cdn.com/v4/letter/e/54ee81/32.png) [@enipla](https://boards.straightdope.com/u/enipla)\ **Post date:** [June 24, 2024, 9:23am UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/17 "2024-06-24T09:23:19Z")
> [@snowthx](#): > > to add more justification for financing the expedition, as opposed to just being a **grand camping trip.** Bolding mine. Thanks for the Monday morning chuckle. ---
**Author:** ![md-2000](https://avatars.discourse-cdn.com/v4/letter/m/9d8465/32.png) [@md-2000](https://boards.straightdope.com/u/md-2000)\ **Post date:** [June 24, 2024, 1:00pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/18 "2024-06-24T13:00:06Z")
It’s possible they were looking for something like the gap the Hudson River provided in accessing the central USA, since nobody knew the exact geography of the northwest. If you read Pierre Berton’s _The Last Spike_ even as late as the 1880’s nobody was sure what the geography of hte northwest looked like on the Canadian side. The surveyors were only winging it a year or so ahead of the builders of the Canadian Pacific Railroad to find the appropriate passes. It’s no surprise that 70 years earlier the geography of the American northwest, with equally fun climate, was similarly unknown. ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [June 24, 2024, 1:45pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/19 "2024-06-24T13:45:31Z")
> [@md-2000](#): > > t’s possible they were looking for something like the gap the Hudson River provided in accessing the central USA, What do you mean there about a ‘gap’? ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [June 24, 2024, 3:06pm UTC](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200/20 "2024-06-24T15:06:32Z")
> [@Railer13](#): > > Correct, as there was a tiny obstacle called Niagara Falls between Lake Erie and Lake Ontario. There was more fhan that. There were the Lachine Rapids near Montreak (they built the Lachine Canal to bypass those) and a variety of other canals to get around other obstacles. Even before they built the St. Lawrence Seaway in the 1950s, there was a system of canals that let traffic go up into the Great Lakes. [Next page](https://boards.straightdope.com/t/what-did-lewis-and-clark-imagine-a-missouri-river-northwest-passage-would-look-like/1003200.md?page=2)