By Denny Dyroff, Staff Writer, The Times Throughout the Mid-Atlantic region, the Brandywine Valley is known for being horse country – an area famous for top-flight equestrian events. The 2017 equestrian season is already underway with a big annual point-to-point event last weekend in Delaware and this weekend’s Annual Willowdale Steeplechase (Steeplechase grounds, routes 82 and 926, Unionville,...