Upper Black Box is a 13 mile point-to-point trail located near Green River, UT. The trail is only recommended for very experienced adventurers and primarily used for hiking.
A Novel could be written on tips for the Upper Black Box canyon but I will do my best to give a few here. We went during the third week of June and did not see another group or person for 3 days so if you’re looking for solitude this may be a good place.
The canyon can be entered in by using one of two ways. The Lockhart Box trailhead and an unnamed wash that will shorten the trip. We entered from Lockhart box trailhead which is a 13 mile trip from start to finish. Total trip time was about 12 hours (with very short breaks). If you start from Lockhart Box it may be more ideal to treat it as a 2-day trip. For the first mile the river is relatively calm and can be easily floated/hiked. The next 9 miles are filled on and off shallow rapids and will require a lot of energy to float/hike. The last 2-3 miles are again calm much like the first.
Entering the canyon from the Lockhart trailhead can be tricky due to the fact that there are several washes that look like trails. This also applies to the exit of the canyon when trying to return to your shuttle car. I would highly recommend scouting out the starting and ending points before entering the canyon which could take a few hours to do.
We parked a truck as close as we could to the end of the big canyon to shuttle us back to our cars at the Lockhart trailhead. It ended up being about a 3/4 mile hike down to the canyon from the Lockhart Box trailhead with an easy cliff approach to the canyon, and a 30 minute easy walkout back to our shuttle car at the end of the adventure. High clearance SUV’s/trucks are the only vehicles that will be able to reach close to the endpoint of the Upper Black Box section. Luckily we had a 1 ton high clearance truck, because our GMC Acadia wouldn’t be able to make it to the end point.
Depending on the water level, there will be several (a bajillion) times where you will get in and out of the water to complete the canyon, especially if you don’t have a tube. As there is little to no established walking trail, prepare to bushwhack your way through the sandbars to the sides of the river.
Plan on staying in the Canyon the whole time. There is a halfway point that you can get out, but it would be like finding a needle in a haystack. 400 foot sheer cliffs surround you at all times so take your time and be careful.
A few tips for the trip:
• Check the weather. This is a slot canyon with high susceptibility to flash floods.
• Bring a waterproof map/compass/and knowledge of how to navigate using them so you can tell how much of the trail you have left to complete.
• Bring a heavy duty inner-tube and life jacket to float down the river.
• Wear swim gear/ Long Sleeve tech shirt to avoid cuts/bruises
• Bring a helmet and at least a 25 foot Rope.
• Bring a good amount of food/water/purifier/first aid/survival gear in case you have an accident or need to camp overnight.
The BLM website explains that you should not attempt the upper black box if the San Rafael River CFS is above 55. When we started our hike it was 160 CFS and when we ended it was down to about 100 CFS. To make the trip enjoyable for walking it may be best to follow the 55 CFS guideline. I did hear from another source that it was safe up to 400 CFS but not totally sure on that. Floating is probably ideal from 175 CFS – 400 CFS.