[2] In 1846, Leroux served as the guide for the Mormon Battalion under Philip St. George Cooke along with Pauline Weaver and Jean Baptiste Charbonneau.
In 1851, Leroux guided the Lorenzo Sitgreaves expedition through Arizona, advising them to explore the Little Colorado River valley, where the party came across the Wupatki ruins built by prehistoric Indians.
[4] By 1853, Leroux had become a wealthy sheep rancher and landowner, but was still open to trailblazing requests (albeit with personal valet).
[5] When returning from the Whipple expedition in 1854, Leroux recorded in his journal an archaeological site in the Verde Valley.
Two days later, most of the party, including Gunnison, was slaughtered when they unexpectedly came upon a group of Paiute Indians.