In 1845 a young man named Isaac Cooper set out in search of adventure. He found it with John C. Frémont's third expedition en route to California across the southern Great Plains. Frémont demanded secrecy about the details of his western forays and forbade his men to keep diaries and journals, a fact that gives credence to claims that the Pathfinder was little more than a filibuster for Manifest Destiny. But Cooper made notes and later wrote The Plains under the nom de plume of François des Montaignes, perhaps still fearing Frémont's wrath. Portions of Copper's memoir were serialized in The Western Journal and Civilian in St. Louis in the 1850's, but until now it has never been published in its entirety. The original manuscript is in the Ella Strong Denison Library at Scripps College in Claremont, California. Cooper, or Montaignes, accompanied Frémont only as far as Bent's Fort, the famous fur-trading center on the Arkansas River in southeastern Colorado. There the expedition split. White Frémont went on to California, Copper turned south with a party of men led by Lieutenant J.W. Abert for the return trip to St. Louis. The people Cooper encountered emerge vividly from the pages of his memoir. There are Frémont, the martinet, and his servant, the obsequious Mesty-Woolah; grizzled mountain men like Thomas Fitzpatrick and John Hatcher; the bombastic old trapper, François La Tulippe, countless Indian; peerless Mexican horsemen; and blundering greenhorns. Cooper presents a whole gallery of western types, including two redoubtable but improbably named army mules, Miss Fanny Squears and Miss Sally Bass. Isaac Cooper's writing is a rare blend of frontier metaphor and urban refinement. Through his descriptions of the region, its people, and it flora and fauna, the Southern Plains acquire a new dimension for scholar and general reader alike.