As we approach the bicentennial of the Lewis and Clark Expedition in 2004 attention will inevitably turn to the nineteenthcentury explorers who risked life and limb to interpret the natural history of the American West. Beginning with Meriwether Lewis and his discovery of the bitterroot the goal of most explorers was not merely to find an adequate route to the Pacific but also to comment on the state of the regions ecology and its suitability for agriculture and of course to collect plant speci