Blackfeet Reservation near Browning, Montana
Leaving the "Grand Falls" of the Missouri on 17 July 1806, Lewis and three companions—George Drouillard and Joseph and Reubin Field—headed toward the Marias River. Lewis's sole purpose was to "ascertain whether any branch of that river lies as far north as latd. 50." If so, that could be used to extend the United States' northern boundary, which had been established by the Paris Peace Treaty of 1783 at 49°37' North, enlarging the territory gained through the Louisiana Purchase to include land north of the headwaters of the Mississippi River, as well as most of the Red River of the North's drainage.
On 19 July Lewis intersected the Marias River six miles above the point where he had ended his exploration of its lower reaches the previous spring. He and his party now continued northwest along the Marias until, on the evening of the twenty-second, its northern source now called Cut Bank Creek appeared to reach its northernmost point. There at "a clump of large cottonwood trees in a beautifull and extensive bottom" (below the bluff at the center of the photo), they made camp, "resolving to rest ourselves and horses a couple of days." Lewis wrote. Inclement weather prevented him from completing the necessary celestial observations, but he had already "lost all hope of the waters of this river ever extending to N. Latitude 50°."
With no game to be found in the vicinity, the four men survived on the remains of some roots and tainted meat they had brought along, plus a few passenger pigeons and one small trout. On the twenty-sixth, Lewis and his detail "set out biding a lasting adieu to this place which I now call camp disappointment."
From Discovering Lewis & Clark from the Air
Photography by Jim Wark
Text by Joseph Mussulman
Reproduced by permission of Mountain Press