What US areas are good for selling horses?

I'd look up polo clubs and find out where the largest concentrations are.

I live on the Third Coast here in Texas, and right now the general horse market is abysmal, especially on the lower end. Polo is its own market though. I'd see if clubs have websites where you could post the animals. Older animals may not sell well at a distance unless they have spectacular performance records and good vet reports.

You won't have any luck in cities as no one has room for horses. If you are looking to sell horses the best place is the country were people are into horses, own horses, and have the capability to care for a horse. States such as Montana, N/S Dakota, Nebraska, Colorado, Texas, etc. So basically the mid west has the highest horse demand. But you can still find many horse buyers in the other states/regions. Such as I have an uncle in the Mountains In California that owns a pack station with something like 100 horses and mules. On my fathers side of the family they took part in founding a town in California, have lakes/ponds, mountains and some other stuff in the region named after us; that would be a long story to tell. Indian fights etc, sorry about getting off topic.

Sell in Spokane Washington that's where I am from and I really want a new horse

North Carolina . Chocked full of horse lovers .... Tennessee too