PA 858 begins at an intersection with PA 706 in the Rush Township community of Rushville. The highway begins its long trek in Susquehanna County by progressing northward in a patch of forests. PA 858, which runs west of a creek, is sparsely populated and homes are rare. PA 858 winds its way in and out of forests, heading on a northeast direction. Soon after, there is an intersection with Keefs Hill Road, a locally maintained highway. After Keefs Hill Road, PA 858 heads back into a dense patch of trees. In the forest, is an intersection with C. Warner Road, and soon after comes one for Shadduck Road.