American Morgan Horse Association (AMHA) 
http://www.morganhorse.com/

The United States Equestrian Federation (USEF)
https://www.usef.org/

Oklahoma Dressage Society (ODS)
http://dressageoklahoma.org/

United States Dressage Federation (USDF)
http://www.usdf.org/

Morgan Horse Club of Texas
http://www.morganhorsecluboftexas.org/

Morgan Dressage Association
http://www.morgandressage.org/