The Schaeffer series is a trail-running event by EX2 Adventures held in Maryland and Virginia. It offers three race distances: a half marathon, a 10K, and a 5K trail run. This event is designed for runners seeking a trail experience over a road race.
The format provides participants with a choice between a longer trail effort, a middle-distance run, and a shorter option. EX2 Adventures also organizes adventure racing and triathlon events, placing the series within the region's wider outdoor endurance calendar.