Palgrave, Ontario – Canadian Olympian David Marcus of Campbellville, ON, and Chrevi’s Capital won both the Grand Prix and Grand Prix Special at the CornerStone Summer Festival held July 12 to 14 at the Caledon Equestrian Park in Palgrave, ON.  Caledon Equestrian Park will be the site of equestrian competition for the 2015 Pan American