The 4K Trail Run is the most unique race in Boston! Taking place on Cathleen Stone Island in the Boston Harbor, teams and individual runners will enjoy an afternoon and evening with their coworkers and friends. After a short ferry ride (~30 minutes) to the island, the event will kick off with a 4K race through the island and end with dinner, beer, and an on-island party.

Every dollar raised from the 4K Trail Run supports Cathleen Stone Island's mission to deliver free, hands-on science learning to Boston's youth. The 4K Trail Run is an excellent way to invest in education of Boston youth and is our most popular corporate fundraising event. This year’s 4K Trail Run will take place on Wednesday, May 21st, and Thursday, May 22nd, 2025 (Teams and runners must select one day to participate).