The anticipated high water in June will drastically change the nature of your trip. Please keep the following points in mind: Do not attempt to navigate the Green River without the proper skills or equipment.
Lifejackets are always a good idea, especially during high water periods. Boaters will experience swift, unpredictable currents and cold water (40-50 degrees Fahrenheit). The swift water elevates the risk of a capsized or flipped boat; the temperature of the water elevates the risk of hypothermia for anyone caught in the water. Top-heavy canoes are especially vulnerable to the strong eddy currents that are prevalent during high water.
Be sure to secure your boats to shore to prevent loss of boats while at camp. Secure your boats using strong ropes and a permanent anchor point such as trees or large boulders.
Campsites will be scarce due to the higher water. Look for trails and openings in the vegetation that lead to camps above the high water line. Consider joining other groups in camp if necessary. Do not make new campsites by destroying vegetation.
Rig your boat safely. Loose ropes and straps create entrapment hazards. Bowlines and other ropes make assistance from motorized craft very dangerous or impossible. Your safety is your responsibility. Do not rely on commercial outfitters or on any rescue personnel for your safety. It is your decision to run the river at high water. Think about how close together your boats should be during high water. Make every attempt to self-rescue if necessary. Talk to group members about emergency and contingency plans before launching on the river. Know your skills. Be mentally and physically prepared. Be safe. Have fun.
Black Box Canyons of the San Rafael Swell warning. Extreme flash flooding and hypothermia danger during the spring, summer, fall and winter months enter at your own risk.
The Black Boxes are a primitive, backcountry experience. There are no signs or marked trails beyond the trail head. Your route finding, canyoneering skills and equipment must be up to the task. During the spring, summer, fall and winter, there is an extreme danger of flash flooding and hypothermia. Even if it is not storming in the immediate area, storms originating near the mountains can cause flooding that will come down through the Black Boxes. Summer showers can raise the flow in the Black Boxes from less than one cubic feet per second (cfs) to more than 2000 cfs in under an hour.
Canyoneering the Boxes requires hiking, floating, wading, scrambling and rappelling. Immersion hypothermia is a real danger, even during the hottest summer days. The sun does not reach the river due to the high canyon walls and the topography dictates that canyoneers spend the majority of their trip immersed in water.
Plan on 12 hours for hiking the upper box and at least eight hours for the lower box. Many parties have been stuck in the canyon overnight because they got a late start.
Both river sections are far from emergency help. Search and rescue is difficult and costly to organize due to communication problems and access into these steep canyons.
Cellular phones do not work in the Black Boxes. Your rescue can put local volunteers in danger. For information about the San Rafael River above the Black Boxes go to KNOW BEFORE YOU GO: FLOATING/HIKING/HORSEBACK RIDING THE SAN RAFAEL RIVER. Be aware of flash flood danger.