The Grass Ridge Combined Driving Event (CDE) began in 2005. It opened a new chapter for the Grass Ridge Equestrian Foundation (GREF), bringing carts and drivers to the Grass Ridge equestrian venue. With driving, as with horse trials, GREF’s mission is to advance equestrians’ education and training for beginners through advanced driving. Grass Ridge offers a three-phase event over three days, dressage on Friday, the three sections of Marathon on Saturday, and the Cones course on Sunday.