Editing Oregon Trail (section)

===Lewis and Clark Expedition===
{{Main|Lewis and Clark Expedition}}
[[File:Carte Lewis-Clark Expedition-en.png|thumb|upright=1.15|Route of the Lewis and Clark expedition]]

The first land route across the present-day contiguous United States was mapped by the Lewis and Clark Expedition between 1804 and 1806, following these 1803 instructions from President [[Thomas Jefferson]] to [[Meriwether Lewis]]: "The object of your mission is to explore the Missouri river, and such principal stream of it, as, by its course and communication with the waters of the Pacific Ocean, whether the Columbia, Oregon, Colorado and/or other river may offer the most direct and practicable water communication across this continent, for commerce."<ref>{{cite book |author = Federal Writers Project |title = The Oregon Trail: The Missouri River to the Pacific Ocean |url = https://archive.org/stream/oregontrailthemi00fedemiss#page/215/mode/1up |series = American Guide Series | location = New York | publisher = Hastings House | via = Open Library | year = 1939 |page = 215 |access-date = January 11, 2013 }}</ref> Although Lewis and [[William Clark (explorer)|William Clark]] found a path to the Pacific Ocean, it was neither direct nor practicable for [[Covered wagon|prairie schooner wagons]] to pass through without considerable road work.<ref>{{cite web |last = Johnson |first = Randall A. |title = The Mullan Road: A Real Northwest Passage |publisher = History Ink |url = http://www.historylink.org/index.cfm?DisplayPage=output.cfm&file_id=9202 |format = Reprint of 1995 article in ''The Pacific Northwesterner'', Vol. 39, No. 2 |access-date = January 12, 2013 }}</ref> The two passes they found going through the [[Rocky Mountains]], [[Lemhi Pass]], and [[Lolo Pass (Idaho-Montana)|Lolo Pass]], turned out to be much too difficult.

On the return trip in 1806, they traveled from the Columbia River to the [[Snake River]] and the [[Clearwater River (Idaho)|Clearwater River]] over Lolo Pass again. They then traveled overland up the [[Blackfoot River (Idaho)|Blackfoot River]] and crossed the [[Continental Divide of the Americas|Continental Divide]] at Lewis and Clark Pass, as it would become known, and on to the head of the Missouri River. This was ultimately a shorter and faster route than the one they followed west. This route had the disadvantages of being much too rough for wagons and controlled by the [[Blackfoot Confederacy|Blackfoot]] tribes. Even though Lewis and Clark had only traveled a narrow portion of the upper Missouri River drainage and part of the Columbia River drainage, these were considered the two major rivers draining most of the Rocky Mountains, and the expedition confirmed that there was no "easy" route through the northern Rocky Mountains as Jefferson had hoped. Nonetheless, this famous expedition had mapped both the eastern and western river valleys (Platte and Snake Rivers) that bookend the route of the Oregon Trail (and other [[emigrant trail]]s) across the continental divide{{mdash}}they just had not located the [[South Pass (Wyoming)|South Pass]] or some of the interconnecting valleys later used in the high country. They did show the way for the [[mountain men]], who within a decade would find a better way across, even if it was not an easy way.