A.C.
I would, in a heartbeat! We had already picked out a place to teach my son basic horseback riding when we found out we had to move (so sad!), but my old neighbor takes her daughter (1 day older than my son, both 4 yrs old) and they're extremely happy with it. I'm jealous, for real.
The lady I know of is in TX, she teaches the kids how to care for the horses, get them all prepared to go, safety, basic riding starting with walking around with the lady right there with them, learning how to use the reins and heel, verbal commands. My old neighbor says her daughter will be posting, whatever that means, soon, but just a little at a time they're learning. But learning that horses are work, too, not just to ride. After the riding lesson, they go back and comb, clean up, all that. I think that's so cool.
Where we recently moved, I've called around a few places and they only teach English style and some stuff I've never heard of....more for shows than for fun, and way too much money. I wanted him around horses so badly though, we've started volunteering at a charity to feed the horses, and he gets to get a little time with them. Not the same, but it's something for now. I don't know what the market for it would be in WA, but if you move to SC gimme a shout.