I graduated from aTm a while ago, but it was very easy (and cheap) to keep my horse in Bryan. The vets are great and plentiful, there used to be a small but active group of eventers and hunter jumper type riders. There are big shows in most disciplines in the Houston area (about 90 minutes away), but weren’t a ton of showing options closer back when i was there. There are feed stores close, but again, the closest real tack stores are in Houston.
As far as general living, you’ll find all the amenities of a college town-chain restaurants, services, etc. the Downtown Bryan area is nice with little shops and local restaurants. HEB grocery stores are great and i miss shopping there. While you can find all types, College Station and aTm are generally much more politically conservative than your stereotypical college town.
What you won’t find is the accessible nature you have in Seattle. It’s flat. There are (relatively) few trees. It doesn’t really rain much, so it’s brown. It’s hot AF much of the time so you won’t want to be outside anyway….it does get real cold in winter, but only for a few days at a time usually.