Word of mouth in the horse world is amazing:o) Also, hand out fliers at a local horse show, write a press release for the local newspaper of the club's events, awards won by members, etc. Most newspapers welcome free copy. Also post meetings on calendar of events again in the paper and/or online sites like the chamber of commerce or other local organizations and bulentin boards
A horse expo or festival of horses is an event that can interest all people in the community with a parade of breeds, riding demos like dressage, reining, or jumping. A costume contest, educational displays, etc.