Canyons are inherently risky. Flash floods occur without notice on sunny days. Technical skills & surrounding topography knowledge required yet does not eliminate risk.
Sure Ain't Heaven!
If Purgatory is a place you have to be in before being somewhere nice, then perhaps the canyon was apply named. Even if it is a place you have to spend time paying hard penance, then again... apply named. You do feel as if you are paying a price making your way up this narrow drainage, and you definitely are wishing and hoping to get to somewhere better... soon.
The first 2.5 miles are in the open and scenic Alamo Canyon basin, walking the rocky wash bottom and the old jeep road on the benches... technically the trail designated 104 (...there ain't no trail, but there are occasionally some carbonite trail markers?) About .2 mile past the t107 turnoff (Roundup Grounds trail)you get to the narrow opening to Purgatory Canyon, on your right. There is a nice, flat top picnic table size rock out in the wash right at the canyon mouth. Do not mistake the canyon drainage at t107 for Purgatory.
Well, this canyon starts off narrow and overgrown, and continues in that vein for it's entire length, at least the portion I explored. The map indicates close to 2.5 miles of drainage topping out over 7500'. I made it up to a grotto'd out gorge, 25' overhanging falls at about 6600', so there is probably about .8 mile more of drainage above where I made it to?? It was not worth the effort getting to where I stopped and turned back, and I doubt if the route would get any better above the grotto, but... for another day, and probably another person, to explore.
Oddly enough, the overgrowth was not all that prickly... it was tree and shrub without thorn, but it was ever present and thick. What rock there was was mostly obscured by overgrowth. It so effectively blocks the path as to slow the progress down to a crawl, and often to a real crawl to make your way under some of the obstructions.
There were a few fun falls to scramble up, and a nice solid bedrock side canyon about a mile or so in. I diverted up it just to get a few minutes of open walking with that pleasant calf burn that comes from those 30 degree slopes.
Perhaps someone else would revel in all that greenery. A different perspective might judge this canyon differently. Check out the pictures and see what you think. Most of them were shot to simply illustrate how closed in this wash is... I was even so distracted by the lack of canyon appeal that I began taking shots of flowers... geez!
So... Purgatory. Go pay your penance! Hope there is a reward for your efforts.
WARNING! Hiking and outdoor related sports can be dangerous. Be responsible and prepare for the trip. Study the area you are entering and plan accordingly. Dress for the current and unexpected weather changes. Take plenty of water. Never go alone. Make an itinerary with your plan(s), route(s), destination(s) and expected return time. Give your itinerary to trusted family and/or friends.