Lower Black Box |

San Rafael Swell

Hiking Lower Black Box - San Rafael Swell Hiking Lower Black Box
San Rafael Swell

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


TICKS & TODOS: 12 Todo Lists / 3 Ticks
CFS RANGE: 0 - 50
CURRENT CFS: Getting current CFS.... Full Details
LENGTH: 7-9 hours
GEAR: Wetsuit recommend, 15 m webbing / rope, inner tube or floatation in your pack
MAPS: Spotted Wolf Canyon, UT
WATER: The stream should be < 50 cfs. It is heavily mineralized, so not filterable to drink.
SEASON: Early spring before run-off, Summer, Fall
NOTES: A 4x4 is required for reaching the trailhead.
Mon Hi:62 Lo:40 Tue Hi:62 Lo:42 Wed Hi:62 Lo:41 Thu Hi:64 Lo:41 Fri Hi:70 Lo:44
View Full Weather Details

The Lower Black Box is one of the classic San Rafael adventures. The hike combines expansive views, with an amazing canyon. Although a classic adventure, it requires skills and good judgment to descend. Even on the hottest days, hypothermia is a real danger. You will be wading and swimming in the river for several hours. For the prepared, this is a magical adventure not to be missed, for the unprepared, it can be a miserably cold experience or worse. Several groups have had very close calls, and lives have been lost in the canyon in accidents in the past. Be prepared!

WARNING: Warning: Be sure to check the river flow before starting the trip ( USGS San Rafael River Real Time Gauge ). The flow on the San Rafael River should be below 50 cfs, ideally below 25 cfs for easiest passage. Also, be prepared for long exposure to cold water, even in the hottest temperatures, hypothermia can be a real danger.

Getting There

Travel to exit 131 on Interstate I-70. This is about 30 miles west of Green River.

  • Take the exit, 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" )
  • You will pass a Sinkhole 5.2 miles from the interstate. ( 12S 534579mE 4308176mN / N38° 55' 19" W110° 36' 04" )
  • At 5.7 miles, a side road goes off on the right. Reset your odometer as you turn off on this side road. The side road is signed Jackass Benches. ( 12S 534569mE 4308980mN / N38° 55' 45" W110° 36' 04" )
  • Follow the side road 1.8 miles to a junction go left here. ( 12S 536839mE 4307607mN / N38° 54' 60" W110° 34' 30" )
  • At 4.5 miles, go right. ( 12S 539032mE 4310348mN / N38° 56' 28" W110° 32' 59" )
  • At 6.2, stay left. ( 12S 541508mE 4310364mN / N38° 56' 28" W110° 31' 16" )
  • 6.7 stay left again. ( 12S 541709mE 4311022mN / N38° 56' 50" W110° 31' 07" )
  • Finally at 8.0, go right. The road deteriorates badly here. ( 12S 541934mE 4312861mN / N38° 57' 49" W110° 30' 57" )
  • Follow the road as far as comfortable. At 11.3, the end of the road is reached at a fence and gate. The road is generally passable with a 4x4, but is very rocky and can be slow going. ( 12S 545905mE 4313110mN / N38° 57' 57" W110° 28' 12" )


From the trailhead, follow the old road past the gate as it heads down to the San Rafael River. As it nears the river, you will reach a junction. Go right, the road quickly drops into a wash. Follow the wash to the river. Where the wash meets the river is the exit point on your return, so take note.

Cross the river, it is normally about knee deep. If it seems exceptionally high, now is the time to turn back. After crossing the river, work your way north and west on the bench above the river. There are many cow trails in the area. Commandeer one that is heading in the direction you want to go. You should be paralleling the San Rafael River. As you follow the river upstream, the cow trails tend to merge and become more unified. It takes an hour to 90 minutes from the crossing to Swasey's Leap. It is easy to recognize Swasey's Leap, as your very near Mexican Mountain, at the entrance to the Lower Black Box. It is impressive how it goes from an open river to a deep canyon in such a short distance.

History Swasey's Leap is named after Sid Swasey. Legend has it that Sid bet his brother, for a herd of livestock, that he could jump this narrow spot on his horse. The leap is likely less that 10 feet across at this point, but as you visit this spot, ponder the take off and landings and make your determination of the legends validity. There was an old sheep bridge at this point, the Hanson sheep bridge, that was build in the early 1900's. Unfortunately it finally succumb to gravity and the elements and collapsed in the late 1990's.

Begin the watery journey

Now is your last chance to change your mind. Be sure the flow is reasonable at this point. Once you start into the Black Box, it's difficult to reverse if the flow is high, and escape options out the canyon walls are few or none. As you start into the canyon, it generally has several deep pools and swims right from the get go, as it narrows and goes under Swasey's Leap. For the next 30-45 minutes, work your way down the canyon, finding ways around or through several large boulder piles. This section is narrow, dark, and exquisite.

About 45 minutes or so from the start, the canyon eases a bit. A few more boulders present obstacles, but overall it is much easier. The canyon also opens and deepens through here, with more options for getting out on sandy benches on the sides to walk out of the cold water. Simply continue down the canyon. It will take 3 hours or so before the canyon walls begin to subside as the canyon opens. The last section, before it opens, has fantastic dripping springs on the walls and vibrant colors. Once the smell of sulfur permeates the air, you know you close to your exit. Exit on the right, where you crossed the river on the approach and follow the approach back to the trailhead.


Printable Maps:
LBB Start

12S 546332mE 4315999mN

N38° 59' 30" W110° 27' 54"

LBB Trailhead

12S 545905mE 4313110mN

N38° 57' 57" W110° 28' 12"


12S 548122mE 4313824mN

N38° 58' 19" W110° 26' 40"


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