On this day in Lewis & Clark history...
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.
From the journals...
July 21st Satturday
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
Platte River near Grand Island
Photo downloaded from http://www.uiowa.edu/~calvin/Nebraska.htm, Photograph No. 874.