I am not sure what you mean by “(possibly) boarding available”. In the Arizona dressage scene, it’s very rare for a trainer to own their own facility. Most trainers here train out of boarding barns that allot them a specific or unspecific number of stalls. Several of the big barns also host other trainers, such as jumpers, western disciplines, Arabian breed specific, etc. That is sort of how it generally works here, most of the time.
I do know a couple of dressage trainers who own their own small barns and have arenas on site. It’s rare but there are a handful.
PM me for any specific names. My own trainer does not have any room in her schedule right now but she has an assistant trainer with whom she works, and I do believe the barn they train out of in Scottsdale has room and, that the assistant also has openings in her schedule. And they both definitely work with Young Riders. I am part of the West-Side contingent so I am not always up on what happens on the Scottsdale side of the business (my trainer teaches out of three barns) but it’s very easy for me to find out.
I’m glad to share more specifics and there are several local people I can recommend other than my own trainer as well as a few I would steer away from.
If you are looking to find your own boarding facility at which no dressage trainer is based, or, to have your horse at home and a trainer to come to you, then you are going to be much more limited in your choices. Most of the more accomplished dressage trainers here aren’t able to travel to teach one client. That has been my experience, anyway.
If you want to ride and train here year 'round, it does help to select a facility with a covered arena. Those tend to be the larger facilities with more going on, like I referenced in the first paragraph.
