I went on vacation (with my wife and daughters) to a ranch (Rankin Ranch) last week. The main activity is riding horses. All guests have to sign a liability waiver which says something to the effect that we indemnify, hold harmless, and promise not to sue regardless of what happens during any and all activities (including horseback riding) while on the ranch. Even though I'm well aware of the substantial danger of riding a horse, I was perfectly happy to sign that form and accept the risk.
I was talking with the ranchers, and they still have a large and very expensive liability insurance policy which imposes a number of restrictions on the types of horseback riding that's acceptable (for example, it's okay to gallop, but the guests have to be in a straight line while doing so) and the ranchers are still extremely worried about losing the ranch to lawyers because some guest gets hurt.
I don't know that much about liability law. Why does the ranch need to be concerned with liability if everyone has signed a liability waiver?