Over 400 colleges in the United States have an ISHA riding team. Most are club sports, but a riding team can be found at many different colleges. I have visited SCAD and attended a clinic there, and they have an amazing facility with the #1 ISHA team in the country for two years in a row. They offer degrees in horse training, selling, and even running horse shows. If you are looking for something more science focused with horses, I have heard Texas A&M has an amazing equine sciences program with an amazing facility, and UC Davis has a very educational and well-known veternary program.
Depends where you're located, what you're looking for, and where you're willing to go! I'm from Canada, and within the country, there are 2-3 good places that I know of, and one within an hour of my city.
There are also different programs within the equine field. There's farrier programs, nutrition, massage, chiropractor, veterinarian, business, general equine sciences, and so many more.
The more you know what you're looking for in a school, and program, and the more you can narrow your desired area of study, the easier it will be to find the program that best suits you. Definitely do a lot of research into the different schools, programs, industries, fields, etc. to help make your decision!