As Phantom said, CTR can really vary by the organization that is putting on the ride. Look into who is sponsoring the ride and what their organization rules are.
I enjoyed doing NATRC for a number of years when I got back into horse. My biggest complaint was that the only NATRC ride in Utah was the one I put one. I lost interest in competing when I had to travel out of the state to Colorado and New Mexico for every ride. That became a 5-10 hour haul each direction. I tolerated that when diesel was 80¢ a gallon. But I have no interest in long trailer hauls when fuel is over $3.50 a gallon.
NATRC rides are mostly weekend events. You show up Friday night, check in and ride Saturday and Sunday. Awards are given out Sunday afternoon and you head home. Most rides are around 40-50 miles over two days, Saturday being longer than Sunday.
You have two judges, One is a Vet and judges the horses conditioning, The second is a Horsemanship judge and will judge how well you and your horse deal with the various obstacles. You are judge on how you camp and care for your horse as well as your time in the saddle. I think it is great experience for anybody who camps with horses to learn how to take care of their horse in camp and on the trail.