CANCELLED. Rescheduled from July 11. Nature Walk focusing on butterfly identification, 11 a.m. at the Dickerson Conservation area. Bring water and a snack. Optional equipment: binoculars and your favorite butterfly ID book. For more information, contact Paul Petkus at papetkus@gmail.com or 773-450-6039 (cell). Walk will be canceled in case of inclement weather. If in doubt, contact Paul.