Since most images are protected by copyright and/or trademark laws, there are legal difficulties in compiling a direct archive of Lewis and Clark related images.

First stop, I recommend perusing our list of Visual Sources & Artifacts.

Looking for Lewis and Clark is an online resource that links to Lewis & Clark images already on the web.

There is also the wonderful List of Lewis and Clark Illustrations from the American Philosophical Society Library. This site includes images directly from the journals of Lewis and Clark as well as associated images such as those drawn by Charles Willson Peale of the specimens returned Lewis and Clark.

Also see the Academy of Natural Science's digital imagery set entitled The Lewis and Clark Herbarium.

Other useful sites include the works of one artist (Jim Wark at AirPhoto), and a list of photographers who can provide original photographs of sites along the Lewis and Clark Trail.

More generally, search for images yourself using Google Image Search or ditto.com, a visual search engine.