Upper Black Box |

San Rafael Swell

Canyoneering Upper Black Box - San Rafael Swell Canyoneering Upper Black Box
San Rafael Swell

Overview | Getting There | Route | Photos | Maps | Comments


TICKS & TODOS: 41 Todo Lists / 10 Ticks
CFS RANGE: 1 - 50
CURRENT CFS: Getting current CFS.... Full Details
GEAR: Standard Technical Gear - Wetsuit in all but the hottest conditions
MAPS: Mexican Mountain, UT; Devils Hole, UT
RAPPELS: 1-60 m ( 197 ft. )(short route), 1+ to 35 m ( 115 ft. ) (preferred route)
WATER: Constant wading and swimming.
FLASHFLOOD: HIGH - River flow also needs to be checked before starting
SEASON: Late Spring, Summer, Fall
NOTES: The trailhead will likely require at least a high clearance vehicle in most conditions.
Thu Hi:79 Lo:49 Fri Hi:80 Lo:52 Sat Hi:78 Lo:50 Sun Hi:79 Lo:50 Mon Hi:73 Lo:50
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The upper black box is my favorite canyoneering adventure in the northern swell. A very short approach and exit, coupled with an incredible stretch of canyon make this one that keeps me coming back. A big thanks to jddiener for pointing out the preferred out, it makes a good canyon even better!

Warning: The flash flood danger in the Upper Black Box is very high. Check the weather forecast before starting, and make sure it has not rained recently and is not going to rain. Check the flow of the river before starting. The flow should be less than 50 CFS. It is a good idea to stop at the San Rafael River bridge by the Mexican Mountain turnoff and inspect the river/wade it to see how deep/cold it is. There used to be a gauge above the bridge you could check on-line, but it has not been operational the last few years.

Getting There

The trailhead starts at the end of the Mexican Mountain road. To get to the Mexican Mountain road, which is near the San Rafael Campground, depends on where you are coming from. Once at the campground, the Mexican Mountain road is on the north side of the river, and well signed just before the cattleguard. (This is also part of the campground.)

  • From the North
  • Just before the town of Castle Dale, at milepost 39.4, go east on the signed San Rafael Swell Access road. Reset your odometer as you turn off the highway onto the dirt road. ( 12S 500218mE 4341289mN / N39° 13' 15" W110° 59' 51" )
  • Continue on this road, passing a cattle guard after 12 miles, and reaching a 4 way junction at 12.7 miles. ( 12S 518059mE 4336281mN / N39° 10' 32" W110° 47' 27" )
  • Continue east at this 4 way junction for 2.4 miles to the signed Buckhorn Wash road. ( 12S 521483mE 4335782mN / N39° 10' 16" W110° 45' 05" )
  • Go right, down the Buckhorn Wash road about 9.5 miles to the cattle guard and San Rafael Campground. ( 12S 529065mE 4326048mN / N39° 04' 59" W110° 39' 50" )
  • From The South
  • Take I-70 west from Green River about 30 miles, to exit 131. Take exit 131, turning right. This road goes east, paralleling the freeway for a couple of miles before turning north. ( 12S 529541mE 4303709mN / N38° 52' 54" W110° 39' 34" )
  • Follow this road 19 miles to where the San Rafael campground is, and the bridge over the river. The cattle guard marks the lower end of Buckhorn Wash. ( 12S 529065mE 4326048mN / N39° 04' 59" W110° 39' 50" )
  • To the trailhead from the San Rafael Campground
  • Head down the Mexican Mountain road. It is 13.7 miles to the end of the road, and several pullouts for parking. The road is generally passable by high clearance vehicles, or very carefully driven cars. ( 12S 544144mE 4318528mN / N39° 00' 53" W110° 29' 24" )


Short Route
From the trailhead, walk back on the road the way you came for a quarter of a mile, to a prominent side canyon on the south (left) side of the road. Rim walk this canyon a short distance on an old road until an easy descent route is found. (There are many options). Descend into the canyon, and follow it a short distance down to where it joins the Upper Black Box. (10-15 minutes from the trailhead)

There is a trail on the right that leads down into the gully. It is loose, so use caution. Downclimb the gully to a flat ledge with 2 bolts and chains on the right. The rappel height is about 60 m ( 197 ft. ). The best approach is to fix your rope here, leave it, then pick it up when you have finished the canyon, saving the weight of carrying it through.

Note: If leaving gear, as recommended, you should be careful to leave the bottom of the rope flaked away from any cracks. People have stuck ropes here when trying to pull it up after finishing the canyon. If you can flake the rope on the ledge 3 m ( 10 ft. ) from the bottom and downclimb the last little section, you should not have any problems.

Take off your harness, put on your wetsuit (if you brought one), and head down canyon. Getting off the boulder pile at the bottom of the rappel is the crux. The pool is generally shallow, so ease in. Jumping could result in injury. The downclimb is straight forward.

Preferred Route
For the preferred route, walk back on the route about 1.5 miles to where the road curves around a side canyon and begins a slight climb up a hill. This is the preferred route canyon. Head down canyon, finding an easy, wide wash in sharp rock for about 15-20 minutes to where the canyon begins dropping and cutting into cedar mesa sandstone. Once it begins to drop, there are several short, easy down climbs until you reach a larger 15 m ( 50 ft. ) drop where several mammoth boulders have blocked the canyon. beginners may want to rappel this. More advanced canyoneers can do an exposed chimney on the right a short distance to a small chockstone, then downclimb under the large boulders and finally down to the canyon floor in a cave like room. This is shortly followed by another easier downclimb on the left.

Five minutes past this obstacle, the San Rafael River comes into view. This is an exquisite place, and is very reminiscent of rappelling into the Zion narrows. Down climb, or rappel the low angle slot on the left until reaching the large perch overlooking the river. There are several anchors here. Choose one, and rappel up to 35 m ( 115 ft. ) meters down to the river depending on where the anchor is extended to. Be sure to test the pull, it can be difficult.

Coil your rope, drybag your gear, and continue down the wide river as it begins narrowing into the Black Box. A boulder section is encountered, but pretty easy to find a way around. About an hour or so after the rappel, you will reach the rockfall at the bottom of the short route. Use caution getting over the rockfall, the water is not very deep, so jumping is not advised. This rock fall is easy to identify, as the entire river passes through a slot on the right, with a dry pile of boulders is on the left.

Both Routes
The rest of the canyon alternates between wading and swimming in most conditions. It takes about 2-3 hours to get to the end of the canyon. Enjoy. Near the end, the canyon has a long, shallow, narrow section to swim, magnificent! Once past this section, the canyon opens immediately. Go left, through the willows, up the first little canyon. Follow this canyon until you reach the old mining road. Turn left on the mining road and follow it back to your car. (a 20-25 minute walk).

If you left your rope at the rappel, don't forget to pick it up on the way out.


Printable Maps:

12S 544126mE 4318492mN

N39° 00' 52" W110° 29' 25"

Best Start

12S 542591mE 4318893mN

N39° 01' 05" W110° 30' 29"

Short Route

12S 543927mE 4318100mN

N39° 00' 39" W110° 29' 33"


12S 544176mE 4317865mN

N39° 00' 31" W110° 29' 23"


12S 545096mE 4318638mN

N39° 00' 56" W110° 28' 45"


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