The two wranglers looked after us very well. First they gave us a useful intro to the basics of horse riding: where the controls were and how to stop. Then they matched us with horses according to our experience (if any) and nervousness/confidence.
The ride is very gentle, although I was amazed at how the horses picked their way safely through the rocks. They're old hands at this. The area is beautiful and so very quiet, especially after a couple of days on the Strip. I was at the back and chatted to one of the wranglers. She was happy to answer my endless questions about horses, riding, western tack and what kinds of wildlife they get up there (lots!).
If you go in winter, bear in mind it's 10 degrees cooler here than the city, whatever time of day it is, and just before it gets dark the temperature drops suddenly. I wore two layers and a ski jacket, plus gloves, and I was still cold at the end of the ride. We all went indoors to eat, and didn't venture outside until we'd warmed up enough to huddle round the campfire.
The food was plentiful, and I was impressed by the vegetarian dinner. I hadn't been sure what to expect but the veggie burgers were great!
Something else to bear in mind is that if you turn up with a bag, you'll have to leave it behind as they don't allow you to get on your horse carrying anything with straps (not even if it's securely fastened to you). You can get a saddle bag to carry essentials like a bottle of water and anything you can't get in your pockets.
It's a great experience and a nice break from the madness of the city, perfect if you don't have much spare time but want to see some of the country.