Editing Yosemite Decimal System (section)

{{Short description|American grading system for rock climbs}}

The '''Yosemite Decimal System''' ('''YDS''') is a five-part [[Grade (climbing)|grading system]] used for rating the difficulty of [[rock climbing]] [[climbing routes|routes]] in the [[United States]] and [[Canada]].<ref name=FoHGrading/> It was first devised by members of the [[Sierra Club]] in [[Southern California]] in the 1950s as a refinement of earlier systems from the 1930s,<ref name=Secor/> and quickly spread throughout North America.