Canyons are inherently risky. Flash floods occur without notice on sunny days. Technical skills & surrounding topography knowledge required yet does not eliminate risk.
What's on the other side of a black hole?
Overview: A semi-technical canyoneering trip with lots of swimming.
Warning: This trip will involve lots of swimming. Everyone in your party should know how to swim. Also you will be in the water for long periods of time. A full length wetsuit is recommended, even in summer. In fall or spring even more may be needed, or at least a much thicker wetsuit, possible hood, etc. Putting floatation in your pack - dry bags, empty 2 liter bottles, etc, will help with floatation. (Note: if bringing bottles be sure to carry them out with you.)
There are several downclimbing obstacles in this canyon. All can be safely descended by experienced canyoneers. Note that reaching an obstacle and jumping is NOT a safe descent technique. If bringing those less experienced, consider carrying harnesses and about 30-40 ft or rope to belay or rappel off of others, with the last individuals performing the downclimb.
DANGER: White Canyon's drainage is immense. Be sure there is no rain predicted on the day you intend to do this canyon anywhere within 30 miles. ALSO - check to see if it has rained anywhere in the area the previous day. People have perished in White Canyon from a flash flood caused by the previous days rain. This is serious stuff, use your brain here over emotion! If it is possible that it has rained or will rain - do this some other day. Also, if you encounter flowing water when reaching the bottom of White Canyon after the hike in, turn around and leave right away, do not attempt the canyon.
DANGER: In 2004 a flash flood created an immense log jam in the canyon that made it unsafe to descend. Log jams 50 ft high formed that you had to climb over (unstable mass jams are very dangerous). It also deposited large quantities of log debris in the slot, making the going very difficult. Within about a year or so another flash flood cleared all this out. In the past few summers a large quantity of wood debris has again been found in the black hole that makes canyoneering very difficult and slightly dangerous. Log debris requires enormous amounts of energy to get through while swimming when in a confined space, be very cautious. Other floods occasionally clean out the debris. The summary is: White Canyon conditions change often, be sure to obtain recent conditions report and judge your ability against the report. Some times will be easier (and more fun) than others. Be prepared for difficult and changing conditions after every storm in the area.
History: Besides a girl's death in 1996 I know of no other specific recent history.
Hike: From the trailhead, head north to the top of the side canyon that allows access down into White Canyon. Carefully climb down the perhaps YDS class 2 gully until you reach the bottom of White Canyon and turn left. At first you will hike along a gravel filled streambed. There may be a little mud and a few boulders, but it is not too difficult. After perhaps 1.5 miles you will reach a point where there is wall to wall water. You can put on your wetsuit here. At first the wades are perhaps chest deep, interspersed with more hiking, but after awhile the canyon will narrow and you will encounter some swimming. Several downclimbs will be reached. Each time you should figure out how to safely downclimb them. Often there will be a swim following a downclimb. The canyon continues with swimming, walking, and wading. The longest swim seemed to be perhaps 100 yards, and you are in the water for the majority of the next 2 miles. When you drop into the black hole (the darkest part of the canyon due to chocked rock and old debris above you) it will get quite dark while you are swimming. You may or may not encounter difficult log jams. Eventually the canyon widens again and the rest of the swimming is optional - though fun, and towards the end it is all hiking again with just a few puddles to wade through.
The exit you are looking for comes just after a side canyon which comes down in at the level of the canyon. 150 yards after this you will see a big pillar on your left. Climb out here on the south (left) side, change out of your wetsuit and do the YDS class 2 climb out of the canyon. If you didn't stage a shuttle vehicle at the exit, walk the approx 2 miles of highway back to retrieve your car.
Water Sources: Nothing you want to drink.
Camping: Options exist off highway 95, none in the immediate area as you wouldn't want to camp at the TH next to the highway.
WARNING! Hiking and outdoor related sports can be dangerous. Be responsible and prepare for the trip. Study the area you are entering and plan accordingly. Dress for the current and unexpected weather changes. Take plenty of water. Never go alone. Make an itinerary with your plan(s), route(s), destination(s) and expected return time. Give your itinerary to trusted family and/or friends.