Editing Yosemite Decimal System (section)

== History ==
In 1936, the [[Sierra Club]] adapted a numerical system of classification. This system, without the decimals, was initially referred to as the "Sierra Club grading system." Class 1 was a hike, and higher classes were more difficult and technical, going up to class 6, which is referred to as [[aid climbing]].<ref name=Secor>{{cite book|title=The High Sierra: Peaks, Passes, and Trails|first=RJ|last=Secor|edition=2nd|page=31|year=1999|publisher=The Mountaineers|isbn=0-89886-625-1}}</ref>

The fifth class began to be refined by climbers at [[Tahquitz Peak]] in [[Southern California]] in the 1950s.<ref name=CAI/> [[Royal Robbins]], Don Wilson, and Chuck Wilts came up with a decimal subdivision of the fifth class consisting of 5.0, 5.1, and so on up through 5.9. This system was implemented in the early 1950s, with new routes and ratings at Tahquitz being described in [[Mimeograph|mimeographed]] newsletters of the Rock Climbing Section of the Angeles Chapter of the [[Sierra Club]].{{cn|date=February 2025}} The system was originally referred to by names such as "Southern California" or "Wilts-Sierra system," but eventually came to be referred to as the Yosemite Decimal System, even though it was devised and standardized at Tahquitz, not Yosemite.<ref>{{cite book|last1=Vogel|first1=R|last2=Gaines|first2=B|year=1993|edition=Interim|title=Rock Climber's Guide to Tahquitz and Suicide|publisher=Chockstone Press|oclc=551221227}}</ref> The first systematic presentation was in the 1956 edition of Wilts's guidebook for Tahquitz. Mark Powell is said to have exported the system to Yosemite around the same time.<ref>{{cite video|title=Open Book: The Story of the First 5.9 Rock Climb|publisher=climbing.com|date=November 12, 2020|url=https://www.climbing.com/videos/open-book-the-story-of-the-first-5-9-rock-climb/}}</ref>

The standards for the fifth-class climbing grades as of 1979 were as follows:<ref name=Wilts>{{cite book|title=Tahquitz and Suicide Rocks|last=Wilts|first=Chuck|date=1979 |oclc=1392029277|edition=6th|publisher=American Alpine Club|url=https://archive.org/details/tahquitzsuicider0000wilt|isbn=0-930410-07-6}}</ref>
{| class="wikitable"
|-
! Grade
! Route
! First free ascent
|-
! 5.0
| The trough
| 1936
|-
! 5.1
| White maiden's walkway
| 1937
|-
! 5.2
| Frightful variation of the trough
| 1944
|-
! 5.3
| East lark
| 1950
|-
! 5.4
| Angel's fright
| 1936
|-
! 5.5
| Ski tracks 
| 1947, 1957
|-
! 5.6
| Sahara terror
| 1942
|-
! 5.7
| Fingertrip
| 1946
|-
! 5.8
| Mechanic's route 
| 1937
|-
! 5.9
| Open book
| 1952 
|}
[[File:Emily Harrington sends Golden Gate (5.13 VI) in El Capitan - 02.jpg|thumb|right|upright=1.15|[[Emily Harrington]] on [[El Capitan]] in Yosemite, [[free climb]]ing a 5.13a route]]
The original intention was that 5.9 would be the hardest possible free climb, with class 6 describing aid-climbing routes. Initially the scale was based on ten climbs at Tahquitz, and ranged from the "Trough" at 5.0, a relatively modest technical climb, to the "[[Open Book (Tahquitz)|Open Book]]" at 5.9, considered at the time the most difficult unaided climb humanly possible. In later years, as gear and athletic standards in the sport became more advanced, many aid routes were "freed" (i.e., climbed without aid), and the class 6 label fell into disuse, so that 5.x could be a label for any technical rock climb, regardless of whether most people were doing it free or aided.{{cn|date=February 2025}} By the 1960s and 70s, increased athletic standards and improved equipment meant that class 5.9 climbs from the 1950s became only of moderate difficulty for some, while new 5.9 climbs were much harder. Class 5.9 began to be subdivided as 5.9- and 5.9+.  Eventually, climbers began adding classes of 5.10 and 5.11 (rendering the "[[Decimal]]" part of the Yosemite Decimal System name technically inaccurate). In the early 1970s, it was determined that the 5.11 climb was much harder than 5.10, leaving many climbs of varying difficulty bunched up at 5.10.  To solve this, the scale has been further subdivided for 5.10 and above climbs with suffixes from "a" to "d".<ref>{{cite news
  | last = Bridwell
  | first = Jim
  | title = Brave New World
  | publisher = Mountain #31
  | year = 1973
  | url = https://web.stanford.edu/~clint/yos/brave.htm
| archive-url = https://web.archive.org/web/20171002033956/https://web.stanford.edu/~clint/yos/brave.htm
 | archive-date = 2017-10-02
 }}</ref>  {{As of|August 2021|}}, only one climb is considered to have a difficulty of 5.15d: ''[[Silence (climb)|Silence]]'', first climbed by [[Adam Ondra]] on September 3, 2017.<ref name="silence" >{{cite news
  | last = Carpenter
  | first = Hayden
  | title = Adam Ondra – Silence (9c/5.15d), a.k.a. "Project Hard", Interview
  | publisher = Rock and Ice
  | url = http://rockandice.com/climbing-news/adam-ondra-silence-9c-5-15d-interview/
  }}</ref>