Cathleen Stone Island, Boston MA
Wednesday, May 20th, 2026
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 around 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 20th, and Thursday, May 21st, 2026 (Teams and runners must select one day to participate).
