“Forest Preserve of Cook County does not have possession & has no right to enter this property or permit others to do so,” the warning reads on a locked gate at Horizon Farm a rolling, 400-acre horse farm in Barrington Hills. The notice was posted by Rich and Meryl Squires Cannon, who assert they are the true owners of the land after they won an Illinois Appellate Court decision in a long-standing legal battle over prized property.