Wandering on a Random Line
In 1905, after Yosemite Valley and the Mariposa Grove were added to Yosemite National Park, the park's new boundary was surveyed. The survey team placed a marker roughly every mile along the boundary. In most cases these markers consist of an iron post surrounded by a pile of rocks and capped with a bronze tablet. Almost all still exist--although the park's boundary, especially in the "timber belt" on the western side, has changed since the 1905 survey, so many markers in this area are not on the present park boundary.
Going clockwise along the boundary from Red Top to Split Mountain, the survey notes are detailed enough that the markers can be located by "running" the survey from a known marker's location to the next marker, converting compass directions and chains and links to GPS coordinates. Where the boundary is defined by township and section lines, the markers were generally placed near section or quarter-section corners--but there are exceptions.
Along the more mountainous north/east/south boundary, the survey wasn't as precise, and markers were placed only at important peaks and passes.
The 1905 Yosemite Boundary Survey