Undertaken from 1804 to 1806, Meriwether Lewis and William Clark"s transcontinental journey of exploration remains one of the milestones of natural history. Mandated by President Thomas Jefferson, who instructed Lewis and Clark to keep careful scientific notes on what they found along the Missouri River and to send specimens of animal and plant life back to Washington at every opportunity, the expedition afforded Americans a glimpse of such exotic creatures as bison, coyotes, and prairie dogs; it also gave them a glimpse of the nation"s future at the dawn of westward expansion. In this guidebook, Daniel Botkin retraces the Lewis and Clark voyage of discovery along the Missouri, inviting his readers to do the same--for, he writes, In this information age, we rarely obtain the information we need most about ourselves, our civilization, and our surroundings. Over and over again I have discovered that Lewis and Clark, two centuries ago, put a yardstick or sextant to things that we no longer seek to pace or measure. Along the way he visits the great prehistoric Indian mounds of Illinois, near the expedition"s starting point; the Platte River, "one of the few major rivers of America that has not been greatly altered by channelization and dams; Yellowstone National Park; and national wildlife refuges in Nebraska, Montana, and other Western states. Botkin"s guidebook suffers at times from encyclopedic dryness, but it remains a useful glove-compartment companion for anyone seeking to follow Lewis and Clark"s passage. --Gregory McNamee