United States Eventing Association - http://www.useventing.com/
USEA homepage

United States Pony Club - http://ponyclub.org/
United States Pony Club website

Equine Now - http://www.equinenow.com/
Looking for a horse?

Saddle Solutions LLC - http://www.saddlesolutionsllc.com/
Saddle Solutions

Eventing Nation - http://eventingnation.com/
The latest eventing news, results, and commentary