Preservation work will address deterioration of the exterior envelope caused by the extreme weather elements of this location and the high visitor traffic to this popular scenic destination. Exterior preservation work includes repairing and securing the unstable stairs that access the observation level; strengthening, repairing and in-kind replacement of railings components; repairing or in-kind replacement of trim, siding boards and sidewall shakes. The height of the railings will remain at the historic level so as not to obstruct the view from inside the observatory. The spacing of the balusters will not be changed from their current spacing. The canvas weatherproofing over the exterior observation level deck will be restored or replaced in-kind and painted. The catwalk grates that protect the canvas will be repaired. The lower level barn doors and the observation level windows and door will be repaired as necessary. Failed mortar joints in the stone masonry of the ground level will be raked out and repointed with mortar mixed to match the existing. The entire exterior of the lookout will be repainted in the same color scheme to match existing. Restoration of the lightning arrestor system is also included in the scope of this work. The Branch of History, Architecture and Landscapes in Yosemite National Park approved this project description.