The Endless Summer 6-Hour Run is a timed race held in July at Greenbury Point on the Chesapeake Bay, with a history dating back to 2011. Participants aim to cover the maximum distance possible within six hours, competing individually or as part of a three-person relay team.
The race features a swift, level 4.37-mile circuit primarily on packed dirt trails encircling Greenbury Point, situated opposite the U.S. Naval Academy across the Severn River. This loop is USATF certified. The race format is well-suited for individuals new to ultramarathons, those using it as a structured long run, and groups of friends opting for a relay split. The event benefits the Semper Fi Fund, a registered 501(c)(3) nonprofit organization.