It's been forever since I've read an animal book, particularly one focused on a horse. I remember reading The Black Stallion and Black Beauty, some Jack London stuff, and whatnot as a kid, but nothing really since. As I recall, most horse stories are about a horse moving from owner to owner, some good, some bad. Most wild animal stories are just a series of mini-crises where the animal bounces along from event to event and occasionally (by coincidence) runs into an animal he knows. Meeting of the Mustangs is a hybrid, doing both.
We meet our central character when he's a few months old and follow him for a couple of years -- he's on his own a lot, and then falls into the hands of some humans -- bounces around a little and eventually comes into his own. Pretty straight-forward animal story, but told with a lot of heart.
Amazon's description puts this at 10-12 year old level -- I think it's probably 7-9, but what do I know about stuff like that? Most of what I was reading when I was 12 wasn't on anyone's age-appropriate list. The writing was crisp and clear, things moved along a a good clip and never dragged on. Kennedy is better at writing animals than people, but it wouldn't take much to fix that (and since the book like something like 80%+ animals, who cares?).
I am absolutely, positively not the audience for this book -- but it wasn't bad, and I enjoyed it. If I was a younger kid who was into animal stories? I'd have really had a great time with it. It's charming, solid and I have no problem seeing it as someone's favorite.
Disclaimer: I received a copy of this from the author in exchange for this post.