Yosemite Decimal System (YDS Class)

I've decided to rate the difficulty of the mountains and trails using the Yosemite Decimal System (YDS), which is generally used by rock climbers. The class is applied to the most difficult part of the trail or route recommended, and usually only applies to certain parts of the hike. Here is the general breakdown of the class descriptions as I'm applying them here:

Class 1: walking only

Class 2: steeper scrambling, occasional hand use for balance; little potential danger

Class 3: steep scrambling, increased exposure (eg. talus); falls are not generally life threatening

Class 4: simple climbing, with exposure; unharnessed falls are potentially fatal

Class 5: technical free-climbing, requires ropes and belaying; falls are generally fatal

Examples of Class 5 climbs would include Cathedral Spires and Devils Tower. I'm not planning on covering technical rock climbing on this blog.

For a good overview of the YDS (and a healthy sense of the general disagreement as to what constitutes each Class), I recommend this site: http://www.climber.org/data/decimal.html