4K Trail Run
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4K Trail Run
The 4K Trail Run is a two-day running event held on Cathleen Stone Island in Boston Harbor on May 20 and May 21, 2026. Participants may register as individuals or as part of a team and must select one day to take part.
The race follows a roughly 4-kilometer loop around the island. Each registered runner receives chip-timed entry, round-trip ferry transportation to the island, a race t-shirt, dinner and beer. The ferry to the island is described as a short ride of about 30 minutes. The event includes an on-island gathering after the race.
Funds raised by the event support Cathleen Stone Island’s mission to deliver free, hands on science learning to Boston youth. The event is also used as a corporate fundraising opportunity and offers both individual and team registration options. Visit the organization's website for the most recent information.
