First of all, endurance is a race as you well know. The AERC sanctions ALL endurance rides in USA & Canada. If you do an endurance in Alaska, the rules would be the same as one in Florida. Distances tend to be longer as you know too. Rider may dismount
Competitive Trail is a timed event. All horses and riders are finishing in roughly the same amount of time, points subtracted if you are too early or late. Essentially, the winning horse is "best conditioned". Riders remain mounted entire ride
With competitive trail, there is a national/Canadian organization, however, they do not sanction rides in all states and provinces. There are many sanctioning organizations, each has a slightly different way of scoring. The North American Trail Ride Conference (NATRC) tends to be in the south and west, some in Canada. They have a rather slow pace for competition (usually about 5 mph). Because of their slower pace, they attract many gaited and pony breeds. NATRC also grades you on your campsite and they set up obstacles and grade you and your horse on them.
I am most familiar with Upper Midwest Endurance & Competitive Rides Assoc. rules (UMECRA). Our pace is much faster, 6-8mph, and we do not judge campsites and horsemanship. However, the faster pace and a scoring system that is heavy on p/r's, the competition is in favor of Arabs and Arab crosses and it is difficult for other breeds to be competitive. My horse has a p/r of 8/1 (for 15 sec.) so we do quite well with UMECRA rules which is why I haven't gone over to endurance. I may do a few days of Shore-to-Shore this year endurance just so I can get off and walk. UMECRA sanctions rides in MI, IN, IL, WI, MN, IA, MB and ND
OAATS (Ohio Arabian and All-breed Trail System) follows the Arabian Horse Association's regional and national scoring rules, just applies it to their open competitions and thus they judge metabolics (dehydration, CRT) as well as p/r's.
Other systems ECTRA (Eastern Competitive Trail Ride Assoc.), SEDRA (Southeast Distance Riding Association), MoTDRA (Middle of the Trail Distance Ride Association) and OCTRA (Ontario Competitive Trail Ride Assoc.) are between UMECRA and NATRC in pacing and scoring though I'm not very familiar with them.
I love distance riding, it's trail riding, and you get a coffee mug at the end!!
In very few other horse sports do you get to gallop along ridges in the Upper Peninsula and swim in rivers and enjoy wonderful scenery all in the same day.
Bantamamba, your mare's got the hind end for it. You'd have to get her in shape though. Izzie, my mare loovvveess it. She gets so bored in the arena, I get her out on the trail and it's like she's 6 yrs old again. I have trouble holding her BACK, lol. Problem is, she's done so much distance that she doesn't understand walking on the trail, especially if we're riding with a big group on unfamiliar trails, she thinks it's competition. My other horse could do both pleasure and distance without bouncing and bolting. Where do you live?
Nearly all distance riders are amateurs. This isn't like showing where you can compete on several horses in one day and therefore make a profit. With the exception of Valerie Kanavy and Darolyn Butler-Dial, NO ONE is professional. Most people just go to a few rides a year and do it because they enjoy trail riding and getting coffee mugs. Most people train their own horses and since you have to condition yourself along with the horse, trainers aren't doing it. In this regard, it's a lot more "grass-roots" than showing.
Why don't you PM me if you want more info?