From their event page: 

Join Fairmount Park Conservancy and YAP (Young and Active Philly) or a 4.5-mile trail run along West Fairmount Park’s historic Trolley Trail. Whether you’re training for an upcoming race, looking to connect with other runners, or just want to get to know the trail system better, this run series provides the perfect opportunity.

Each trail run will be led by a Fairmount Park Conservancy staff person, in partnership with local run club leaders (see schedule below). At a few points along the run, we’ll stop and talk about the past and present of the Trolley Trail, which roughly follows the route of the old Fairmount Park Trolley that operated from 1896-1946. We’ll even run through some of the physical remains of what is now a hidden trolley network.

Each run will have multiple pace groups; however, in order to finish before sunset, runners should be able to consistently run for 4.5 miles on trails. While this run series is in partnership with local run clubs, you do not need to be part of the run club to attend. Each event will be a mix of runners from that club and runners from the general public. Join for one run or for all four!