Mexico flows and Mesquital follow up
In general, the best timeof year for the three rivers I've done is probably January through March. These are very technical runs and you hope that the action doesn't get too fast to handle. Low water abviously means things are more sievey, but coined the phrase "It's bangable." ... being glad to have lines without being cartwheeled and (Stern Heavy) rear endering through class V all the time. Sometimes the put-ins may only be 200 cfs and by trip ends your somewhere between 500 - 1000.
Steve Daniel's is the guy that lost his legs. It was 1987 when I had to cancel at the last moment on that trip. It was a large group and within the first 20 miles Steve ran over a horizon line without scout. Vertically pinned and boat taco -ed in half forward, Tom Monfzinger and Steve Morgan rescued him and floated through rapids resucitating him. Then a couple of days hike for help and an amazing military helocopter landing in the gorge flew him out. Both legs had to be amputated. Steve Damiels was, and probably still is, a professor at Texas A&M. Nofzinger, Morgan and I went back and conquered the run the next year.
I caution anyone doing these trips: With self supported stern heavy boats we had numerous other close calls. Factor in this unique complication when determining your ability to make the many must make lines in these canyons. These are completely remote locations and truly awe inspiring in many ways. To counter the delima of heavy boats, when doing the Moctozuma we planned to have sherpas hike into the canyon at various locations with food and provisions. Unfortunatley the walls were 2000 vertical most the entire way and we starved for 6 days as we struggled to get through alive. At several juntures, the trip seemed we stuck with no way through. Todd Hebblewhite and Tom Nofzinger (both now deceased from non-boating related deaths) performed amazing feats to find and prove ways through the seives between vertical walls with no banks. Purposely pursuing vertical pins to allow climbing out onto middle of the river portages of house size boulders while white death raced on all sides required cat like agility. Todd was amazing to watch, and we were fortunate to have pure and determined heart on that trip. As mentioned before, anyone attempting this run will also encounter a non-scoutable, non-portagable, blind turn, horrific Z drop. You know you're going to get clobbered, but there is no other choice. Fortunately, we all got spit out through one slot or another at the tail end. Many of these adventures are not mentioned in the Gringo's Guidebook because the author and his brother hiked out at the only midway chance that presented. They had a troublesome time getting out, but had had enough swims and seemingly hopeless experiences in the first few days that they were willing to take their chances on land. We thought we'd never see them if we made it through, but they were at the take out, along with our sherpas, when we emerged. It was quite an adventure, but not one that I would highly recommend attempting again. That was in 1985, I think another group did try it in the 90's, but I never heard how they faired. Copper Canyon, on the other hand, I highly recommend. It has it share of hair boating, but seems a bit more accessable for escape or help if needed.
Cheers to all that enjoy adventure!