Published by historian Richard R. Smith, Lewis & Clark in Lemhi County, Idaho: August 12-September 4, 1805 meticulously chronicles the Corps of Discovery's harrowing and pivotal traverse through the rugged continental divide. The book details the expedition's difficult encounters with the geography and the Agaidika (Salmon Eater) Shoshone people, highlighting the critical diplomatic negotiations and horse trades that ultimately enabled their passage over the Bitterroot Mountains. Drawing on journal entries, cartographic records, and local terrain analysis, the text traces the exact footpaths and campsites used during this grueling three-week window. A keen insight drawn from the work is how the expedition’s survival in the Salmon River country completely inverted the explorers' geographic expectations; instead of discovering an easy water route across the continent, Lewis and Clark were forced to humble themselves before indigenous mountain pathways, realizing that the West could only be crossed through collaborative reliance on native survival expertise.