What is Yosemite Decimal System?
The '''Yosemite Decimal System''' ('''YDS''') is a system that is used to [[Rating system|rate]] the difficulty of walks, [[Hiking|hikes]], and [[Rock climbing|climbs]]. The system has three parts. It is used mostly by [[Mountaineering|mountaineers]] in the [[United States]] and [[Canada]]. ==YDS Classes== The YDS system divides all hikes and climbs into five [[classification|classes]].<ref> {{cite book | last = Roper | first = Steve | title = The Climber's Guide to the High Sierra | url = https://archive.org/details/climbersguidetot00rope | pages = [https://archive.org/details/climbersguidetot00rope/page/19 19]–21 | year = 1976 | publisher = [[Sierra Club|Sierra Club Books]] | isbn = 0-87156-147-6 }}</ref> Classes 1-3 are used mainly in hiking and [[trail running]]. *If a trail is rated Class 1, a person can walk on the trail with very little chance of getting hurt. Wearing hiking boots is a good idea. *If a trail is rated Class 2, a person can 'scramble' up the trail. They may need to use their hands every now and then. There is little chance of getting hurt. Wearing hiking boots is important. *If a trail is rated Class 3, a person can still 'scramble' up the trail, but they need to be able to hold on with their hands. If a person is just learning to climb, they should use a rope to make sure they are safe if they fall. Falls from Class 3 trails could kill a person. If a trail is rated Class 4, a person will have to do some simple climbing to get up the trail. There is a lot of natural protection on the trail (like parts of a rock wall that are easy to step on or grab onto.) Often, people use ropes for safety on Class 4 climbs, because falls from Class 4 climbs could easily kill a person. The Class 5 part of the system is used mostly in [[rock climbing]]. A person needs to use a rope for safety when they climb a Class 5 climb. The person may use a [[Belaying|belayer]] or other protection hardware for safety. If a person falls from a Class 5 climb without being attached to