 The journals kept by Cook and Folsom, as well as their personal accounts to friends were of significant inspirational value to spur the organization of the Washburn-Langford-Doane Expedition which visited Yellowstone in 1870.The party of three explorers departed Diamond City, Montana  on September 6, 1869 and traveled up the Missouri River to Three Forks, Montana.They then began the easterly march up the Gallatin Valley, stopping in Bozeman, Montana for supplies on September 8, 1869.