 The word "Pony" in United States Pony Clubs does not refer to the type of horse allowed in the club, but instead to the fact that their members were required to be younger than 21 upon the establishment of the club.Beginning in 2001, USPC raised the "graduation" age of members to 25 and also added programs on western riding and issues such as land conservation.The USPC has over 600 clubs or centers, and over 10,000 members in the United States.