An Infamous One. The South Fork of Choprock Canyon is known by several names. The first descenders (Jenny Hall and Mike Bogart, June 24 and 25, 1982) named it Kaleidoscope as it presents a different view with every turn. Others have called it simple Choprock (which is misleading, as Choprock has several forks) and Chopslot, and Choprock Slot. Around the campfire, it is known as simply “Choprock”, with the context that we are talking technical canyons; we will choose the same nomenclature here.
Choprock has a checkered history, much like any canyon that becomes more popular after someone dies or is rescued from it. The canyon shows a big difference of difficulty with how much water is present. In normal conditions, Choprock makes for a long and strenuous day, including many hours of swimming in cold water. The spring of 2005 was unusually cold and wet, and early-spring conditions persisted into May. Two young men entered the canyon poorly equipped for normal summer conditions, and died of hypothermia. Read the warnings carefully to be fully prepared.
Choprock is a long and difficult canyon. The canyon starts with a lengthy approach, and has long, pleasant and wet sections before arriving at the "Grim Section", where the possibly difficult, bell-shaped slots are located. There are fully four hours of swimming before the first of the technically difficult obstacles is found.
Well, well. On that cheery note, what is there GOOD to say about the canyon?
It is a nice one, one of the best. It can be very difficult, and should always be taken seriously. It is not a place for "Youth Groups", college outing club adventure hikers, or "experienced outdoorsmen". It is a place for experienced canyoneers.
In addition to the flooded, bell-shaped slots, Choprock CAN be jammed with an awful lot of wood debris, washed in by flashfloods from the benches above. As little as five years ago, the canyon was MUCH more difficult, requiring extensive climbing over unstable woodjams, swimming underwater in the dark, and other "fun" solutions to problems. In 2001, a massive flood temporarily cleaned the canyon out, and now the lower section is relatively easy again. It could fill back up and go to "difficult" conditions at any time.