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.
3B IV ★★★
When full: 4B IV R ★★★
Described as a long dayhike from camp at the mouth of Fence Canyon.
Spring, summer, or fall
90 feet (30 m)
Helmets, rappelling gear, webbing, rapid links.
COLD WATER PROTECTION
Highly variable, wetsuits generally required.
Bring your own water.
FLASH FLOOD RISK
Choprock involves many hours of swimming and wading. In normal, summer conditions, a "full thickness" wetsuit will be required: meaning a full arms, full legs wetsuit of at least 4mm thickness. In spring (which can be anytime March-June), a little more may be required. Because of the extensive slot-climbing, this is not a good place for a dry suit. At the end of the summer, in full drought, a summer-weight full-full 3mm wetsuit may be acceptable.
Is more gear better? Nope! While you will need a bit of rope and maybe 10 feet of webbing for re-rigging anchors if needed, more gear will just get in the way of the kinds of problems found in Chopslot. When working your way through the narrow slots, you will be very happy to have less stuff to drag along behind you.
Everyone Fit and Strong: Partner climbing is a big help, but really, in Chopslot, everyone needs to be capable of climbing the problems. While there are not a lot of climbing problems in normal conditions, in high-water, there can be extensive climbing required.
A Long Day in a Wilderness Setting: Once in the canyon, there is no escape until the end. You are on your own. Be 100% responsible for your own safety because, well, it's true here more than anywhere.
Size Limit: Large people could have considerably more difficulty in this canyon, and might have to go over in places we normally go through.
OK, enough of the gloom and doom. Onto the actual Beta. Since this is an advanced level canyon, the actual beta will be slim. Deal with it.
This canyon has less "seasonal" adjustments as it does "water level" adjustments. Choprock is one of the few canyons on the Colorado Plateau that becomes more difficult with more water in it. We usually think of canyons as being colder, but easier, when full. Most canyons have pothole problems, which are easier or no problem at all when full. Choprock is not like this.
In Choprock, the problem is flooded slots and wood jams. The slots are narrower above, so as the water level increases, the space for passage becomes smaller. Eventually, there is not enough space, and one must climb up, out of the slot and traverse above. Because the canyon is belled-out at the bottom (ie, wider at the bottom), and because the slot walls are slimey, the climb up can be very difficult. Wood jams in the slot can make this even more difficult.
Starting your day
Get an early start. Chopslot makes for a long day, and the approach hike is much more pleasant during the cool hours of the morning. We usually leave camp a half-hour before dawn. Earlier if the days are short. Rappels in this canyon are few and far between. Many people will prefer to take off their harness between rappels.
From a camp near the mouth of Fence Canyon, cross the Escalante River and follow a trail on the other side up-canyon. Near where the trail first approaches the canyon wall, ascend an easy slickrock slab to the first bench and traverse northward. Work your way up until you are on the Overland Trail. Follow this north to the first side canyon, then follow the sidecanyon east to the benchlands above. Hike east, into the rising sun, across the top of one mesa. At the second mesa, cut left onto the shoulder of mesa 5776T. Find a 4th class chimney to get down the cliffbands and down to the slickrock benches. Continue east until it is possible to walk down into the bottom of the canyon.
Walk downcanyon. After 15 minutes or so, it will start to slot up. You will soon be swimming, so suit up here. After clambering through some boulders and slots, a downclimb or rappel is followed to a pool. Swim. Hike another 15 minutes to the next obstacle, which will require a harness. Rappel 80 feet into the Riparian Ballroom, and the start of the Riparian Section.
The Riparian Section
Super-nice. Springs produce abundant water that makes for a jungle of growth - horsetails, cottonwoods and poison ivy dominate the scene. Wade through the water or bush-whack along the shore. Very enjoyable.
The Happy Section
Eventually the canyon narrows up and the abundant growth disappears. New springs refresh the water, now flowing a little colder and clearer than in the Riparian Section. Stop for an early first lunch before launching into the water.
The Happy Section alternates long cold swims with nice walking through slots, plus a couple of downclimbs. The course of the canyon switches back and forth, so at times it catches the sun. It is - happy. A short rappel from a single old bolt marks the end of the Happy Section.
The Grim Section
If the canyon ended here, it would be an amazing classic visited and enjoyed by all. But it doesn't, for the canyoneering part of the day is but half over. The GRIM section is where the action is, and is made more grim because basically, you're tired, getting cranky, a little cold and ready to head back to camp for a nap. Not yet.
The canyon narrows again, and the sun is seldom-seen. The canyon is characterized by long corridors, either sandy or flooded, wide or narrow, easy walking or difficult swimming. In a few places, narrow, bell-shaped corridors offer the possibility of difficult climbing problems. At medium water level, take your helmet off in order to swim through, and in a few places, push yourself downward to find a spot wide-enough to get through. Other places require climbing on unstable wood-piles, pushing through log soup, or scurrying above narrow slots, only to have to find a place wide enough to slip down through the slot and into the pool below. There are several 100-foot-plus swims through windy, multi-chambered passages. Have a good time, try to stay warm.
Toward the end is my favorite feature. A narrow slot extends above a long pool. Entry into the pool requires squeezing down through the slot, then dropping into a pool of unknown depth. Or does it? Near the head of the slot, potholes are sunk into the floor, almost at pool level. Perhaps there is a way through?
A unique canyon
Choprock's Riparian section. After walking the slickrock down into the canyon, wander downstream a few minutes to where it slots up. A quick downclimb, a couple swims and a rappel, and you are in one darn beautiful spot, the Riparian Ballroom, and the beginning of a remarkable riparian section unique in my CP canyon experience.
Water water everywhere...
A Choprock descent can vary greatly based on canyon water levels.
At last, the bleakness of the Grim Section is broken by a ninety foot rappel back to the land of the living.
Hike down the South Fork of Choprock until meeting with main Choprock Canyon. Poison Ivy is again one of the main plants. At the main canyon, turn left and hike a mile down to the Escalante River, then a mile down the Escalante to the mouth of Fence Canyon.
Now you can take your nap!