This photo needs editing.
Difficulty III-V
Length 42 Miles
Flow Range 375 - 900 CFS
Flow Rate as of: 50 minutes ago 0 [CFS]
Reach Info Last Updated 04/30/2019 6:32 pm

River Description

SEASON: Spring snowmelt. Usually a couple weeks around late May to June.

FUN FACT: An amazing Utah Canyon

ACCESS: Put-in at the bridge near the San Rafael Campground, which can be accessed from the north by a road that leaves Highway 10 or from the south by a road that leaves I-70. To reach the take-out, there is a rough road that parallels river left and takes you close to the end of the first Black Box (about 16 miles of very slow driving--i.e. you could Mt. Bike it faster than you can drive). For those who plan to continue on through the second Black Box the I-70 bridge (mile 145) is the best take-out. Either one of these shuttles takes a long time so prepare accordingly.

DESCRIPTION: First explored in the early 70's on trips led by Cal Giddings, the Black Box section of the San Rafael cuts through one of the most amazing canyons to expose the geology of the San Rafael Swell. For those planning to run both Black Boxes prepare for an overnight trip. It takes a long time to work your way through the canyon sections and the portages are hard. While the rapids themselves rarely get above class IV, there are plenty of dangers in the canyon in the form of rock sieves, limited access options once you're in the canyons, and no possibility of outside help if you get into trouble. You might think of it as a class IV trip with class V consequences. Beware of high water. Once you're committed there is no pulling out--first-time exploratory runs are best done at the lower limit of flows.

The river starts out as an easy float downstream from the campground and the first ten miles consist of swift-moving current with little actual whitewater. There are a couple class II riffles, but the action doesn't really start until the walls begin to close in on both sides--the start of the first Black Box section. The rapids start out as easy class II with occasional class III thrown in. The pace picks up again with boulder choked passageways requiring class III and IV moves. There are a couple spots in here where the entire river drops through boulder sieves--use extreme caution as you approach any blind corner. Expect to make a couple of portages over house-sized boulders. It can be a challenge getting back into your boat after a couple of these and they take a lot of time.

As Mexican Mountain comes into and the canyon opens up again you've come to the end of the First Black Box. Going around the bend at Mexican Mountain you'll float through about 5 miles of swift but mostly flatwater. This is a good spot to break for the night if you're making an overnight trip.

The Second Black Box is even more constrained, just a bit more challenging, and somewhat shorter than the first. Expect some steep boulder drops, some of which must be run blind above 400 cfs.

For packrafters, the Black Boxes provide a quintessential wilderness adventure trip best run as a three day loop. Start with a hike in from the west via Drowned Hole Draw to a put-in at Lockhart Box and a take out at the bottom of Black Dragon Canyon/ I-70.  A mountain bike shuttle up Black Dragon completes the loop.  300-400 CFS is ideal.  Expect to encounter 10-15 portages, a couple obligatory class IV drops and jaw dropping scenery. 

lat/long approximate by tiger map server

for additional information see:

  • Nichols, G.C. 1993. River Runners' Guide to Utah. University of Utah Press, includes an excellent and comprehensive description.

Rapid Descriptions


Gage Descriptions

Levels are approximate. Around 450 is a good level for a first-time exploration (although some might find it a little bumpy). Routes would become more congested at lower water. Higher water would smooth things out a bit, but you need to be in control as the current picks up and remain aware of several rock sieves.

Directions Description

We have no additional detail on this route. Use the map below to calculate how to arrive to the main town from your zipcode.

No Accident Reports



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Bill Introduced to designate new Wilderness and Wild & Scenic Rivers (UT)

Nathan Fey

Washington, DC –  Today, Senator Orrin Hatch (R-UT) and Representative John Curtis (UT-3) introduced the Emery County Public Land Management Act of 2018, a historic conservation bill protecting over one million acres of public land, and 98 miles of Wilderness and Wild & Scenic Rivers in Utah’s Emery County. American Whitewater worked to ensure that the Green River, Muddy Creek, and the San Rafael are protected under the legislation.

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Green River Boat Passage Officially Open! - UT

Kestrel Kunz

American Whitewater staff traveled to Green River, UT in late March to meet with private water users and state agencies, and to participate in the official opening of the new boat passage through the Green River Diversion (Tusher Dam). Completion of the boat passage has freed the Green River from its last in-stream obstruction between the Flaming Gorge Dam and the confluence with the Colorado River – over 400 floatable river miles through iconic canyons and historic landmarks. It has a been a long process, and our work isn’t over yet! As your boating representative, American Whitewater will continue to work closely with the dam operators and Utah’s Division of State Lands (FFSL) to ensure that the boat passage meets the needs of the public during its inaugural year.

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Flow Study on the San Rafael (UT)

Nathan Fey

Green River, UT - With flows of over 350cfs, Utah's San Rafael River is drawing lots of visitation this week from paddlers.  If you have paddled the San Rafael - please take a minute to help us identify how flows affect paddling opportunities by participating in a quick on-line survey.

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American Whitewater Weighs in on BLM Oil Shale and Tar Sands Plan

Nathan Fey

The Bureau of Land Management is considering the potential for oil shale and tar sands development on 2,431,000 acres of public land in Utah, Wyoming and Colorado. This development could threaten the quality of paddling experiences including the multi-day desert floats on Desolation and Grays Canyons of the Green as well as the adventure available for kayaks and packrafts to explore the San Rafael, Muddy and Escalante. American Whitewater partnered with our colleagues in the Outdoor Alliance to highlight the value of these areas for outdoor recreation.


David Nix


Kestrel Kunz


Thomas O'Keefe


Revision #Revision DateAuthorComment
1212090 04/30/19 David Nix updated description
1207972 07/09/17 Kestrel Kunz Reach # fixed
1191667 06/13/01 Thomas O'Keefe n/a
1196492 11/14/09 Thomas O'Keefe
1196493 11/14/09 Thomas O'Keefe
1199936 04/27/11 Thomas O'Keefe edits