This book is designed to help passengers better understand what the Lewis and Clark expedition experienced during those momentous years of 1804-1806, but also to be able to see through vintage photographs and other images what the members of the Corps of Discovery saw before the rivers were changed forever by hydroelectric dams. It affords an opportunity to travel "in the wake of Lewis and Clark." Leaving St. Louis on May 14, 1804, with thirty-four soldiers, hired voyagers, and Clark's slave, York, they traveled through the unexplored territory and beyond it, to the Pacific Ocean. Their exploits come alive today as cruise ships travel their route up and down the Snake and Columbia Rivers.