Elkhorn Ranch was founded in 1922, and in the last 96 years they've learned quite a bit about how to create a great family experience.
The ranch has a recommended structure -- full day rides on Tuesday, Thursday, and Saturday; breakfast on the trail on Wednesdays; dinner on the trail on Thursdays; and a square dance friday night; kids and adults generally ride separately. But there's a lot of flexibility, too. My group opted for more family rides, and cut some of the full day rides down to half days -- it was all easy.
My city slicker kids took to Elkhorn like fish to water. They'd never ridden horses before, but they loved riding and getting to know their horses. While they usually detest "kids clubs" at upscale resorts, they loved hanging at the kids rec hall, or down by the swimming hole, and ditching the adults. In general, they got to experience a freedom at Elkhorn that they don't often get at home -- able to ride a horse, come and go as they please on the ranch, yet operate in a small enough space that they could find us whenever they wanted.
To say the meals were hearty would be an understatement. They were massive three times a day, and I had to learn a bit of self control as the week went along. Being on a horse is cardio for the horse, not me.
Possible negatives: It's not a resort -- the accommodations are rustic in nature, there's no gym or massage option, and there are no TVs or even wifi in the cabins (there is wifi in the central office). Also, if you have dietary restrictions, it can be a bit more challenging. This is not where you go to be pampered.
Overall: Elkhorn Ranch exudes family fun. It's built for kids and grown ups to enjoy together, and has been operated by the same family for generations.