 Word of their journeys inspired the New Mexican merchant Antonio Armijo in 1829 to establish the first route for mule trains and herds of livestock from Nuevo Mexico to Alta California through the area, along the Virgin and Colorado Rivers.Called the Armijo Route of the Old Spanish Trail, the route was later modified into the Main Route by the passing merchants, trappers, drovers, Ute raiders and settlers over the years by moving to a more direct route.In Clark County it was northward away from the Colorado to a series of creeks, waterholes and springs like those at Las Vegas, to which John C. Frémont added Frémont's Cutoff on his return from California to Utah in 1844.