In late July, the Corps of Discovery, canoeing against the strong current of the Missouri River, passed the red-hued cliffs known as Crimson Bluffs on the west side of the river on an early summer morning. The journals recorded a remarkable crimson-colored bluff, intermixed with strata of black and brick-red slate, and Sgt. Gass noted passing a bank of very red earth that Native people used for paint. York's Islands, visible upriver to the south, were another landmark noted in the journals. Today, the bluff's iron-laden earth appears vibrant red when lit by the sun's early morning rays, and the area is managed for public enjoyment by the Bureau of Land Management with assistance from the Crimson Bluffs chapter of the Lewis and Clark Trail Heritage Foundation.