The early trails of Yosemite largely followed those of the Miwok and Paiute natives who traveled routes into Yosemite Valley and across the Sierra Nevada Mountains to trade. Early visitors finished their trip into the valley on horseback down either the Pohono or Oak Flat trail. Sheep ranchers brought their flocks into Yosemite's high meadows from both the east and west following one of the branches of the Mono trail. And Army troopers assigned to protect the new Yosemite National Park ushered shepherds and their flocks out of the park (usually in opposite directions1) following and building on trails first traveled by Yosemite natives.
1H. Duane Hampton, How the Calvary Saved Our National Parks, Bloomington, Indiana: University of Indiana Press, 1971.