<Li> June 3--20: Marias River to the Great Falls . </Li> <Li> June 3: The mouth of the Marias River is reached . Camp Deposit is established . Cached blacksmith bellows and tools, bear skins, axes, auger, files, two kegs of parched corn, two kegs of pork, a keg of salt, chisels, tin cups, two rifles, beaver traps . Twenty - four lb of powder in lead kegs in separate caches . Hid red pirogue . Natives did not tell them of this river . Unable to immediately determine which river is the Missouri, a scouting party is sent to explore each branch, North fork (Marias), South fork (Missouri). Sgt . Gass and two others go up south fork . Sgt . Pryor and two others go up north fork . Can't decide which river is Missouri . Clark, Gass, Shannon, York and Fields brothers go up south fork . Lewis, Drouillard, Shields, Windsor Pryor, Cruzatte, Lepage go up north fork . Most men in expedition believe north fork is the Missouri . Lewis and Clark believe south fork is Missouri and followed that fork . </Li> <Li> June 13: Scouting ahead of the expedition, Lewis and four companions sight the Great Falls of the Missouri River, confirming that they were heading in the right direction . Lewis writes when he discovers the Great Falls of the Missouri . "When my ears were saluted with the agreeable sound of a fall of water and advancing a little further I saw the spray arrise above the plain like a column of smoke...began to make a roaring too tremendous to be mistaken for any cause short of the great falls of the Missouri ." </Li> <Li> June 14: Lewis takes off on an exploratory walk of the north side of the river . Lewis shoots a bison . While he is watching the bison die, a grizzly bear sneaks up on him and chases him into river . </Li>

How many were in the corps of discovery