July 21, 1804
The Expedition sets out at sunrise and passes the mouth of the Platte at midday. They notice its roiling sands coming into the Missouri channel. The evening camp is southeast of present Bellevue, Nebraska.
the Sands of this river Comes roleing down with the Current which is Crowded with Sand bars and not 5 feet water at any place across its mouth, Capt Lewis & my Self went up Some Distance & Crossed found it Shallow. This river does not rise over 6 or 7 feet
July 21, 1805
Lewis leaves early and passes through the Spokane Hills into the Helena valley. Seaman chases geese. Ahead, Clark concludes his search for the Shoshone and returns to the Missouri River to lay in a store of meat for the main party.
Set out early this morning and passed a bad rappid where the river enters the mountain about 1 m. from our camp of last evening the Clifts high and covered with fragments of broken rocks.
July 21, 1806
Near present Cutbank, Missouri, Lewis suspects that the Marias will not head any farther north. At the canoe camp on the Yellowstone River, half of Clark's horses disappear during the night. The horses at the Great Falls are also missing.
we found the ravines which made in on this side were so steep and numerous that we passed the river in doing which the pack horse which carried my instruments missed the ford and wet the instruments.