SUMMIT AREA – On Tuesday, October 28th at 9:30 a.m., the Summit Area Old Guard will hear Timothy Rack, Manager of Safety and Compliance of the Morris County Park Commission, speak about the three sinkholes that have recently appeared on and around Interstate-80. Mr. Rack will explore the history of mineral mining in NJ that has led to abandoned and often forgotten mines, and how they may now pose a threat. Tim is responsible for both employee and visitor safety within Morris County’s Park system.