view southwest, upstream
At 4 P.M. on 1 June 1804, the expedition arrived at the mouth of the Osage River (left fork in photo), one of the major Indian fords on the lower Missouri. From a promontory between the rivers, Clark wrote: "I had a delightfull prospect of the Missouries up & down, also the Osage R. up." The point of land on which he stood may have been nearly four miles west and two miles south of where it is in the photo.
That night and the next morning Lewis took astronomical observations to measure the latitude and longitude of the place. The raw numbers for longitude would be passed on to a mathematician after the expedition, since the trigonometric formulas involved in that were too complex and time-consuming to be worked out en route. However, Lewis determined the latitude, which was easier to compute, as 38°31'6.9" north.
On 26 May, thirty-five miles downriver, George Drouillard and Pvt. John Shields had been sent ahead with the expedition's two horses to "proceed on one day and hunt the next," but they missed their rendezvous with the boats. On June 2nd they finally caught up with the main party, "much worsted" but giving "a flattering account of the Countrey" they had seen. Their experience reminds us that the Corps of Discovery's trek through the Northwest was anything but an orderly march. Frequently hunters, or even one of the officers, ranged many miles on either side of a river, either intentionally or not. Nearly every step each man took was an important part of their exploration.
The Corps passed the Osage River again, without comment, on their journey eastward on 20 September 1806 – three days from home.