Lewis and Clark were blown away by the thousands upon thousands of bison they saw storming across the open plain. It seems every time they turned around they spied a grizzly bear on a hillside. And the salmon were so thick in the rivers, they could have walked across the backs of them to get to the other side.
But... no more. Populations of bison, grizzly and salmon have greatly diminished, and some plant and animal species have gone extinct, or are on the brink of it.
Find out what Lewis and Clark observed about the following plants and animals -- and what's left today.
