4K Trail Run
- Date
- May 20, 2026
- Distance
- Wednesday 4K Trail Run - Individual Registrations · Wednesday 4K Trail Run - Team Registrations · Thursday 4K Trail Run - Individual Registrations & more
From the Organizer
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).
Distances & Pricing
Race Location
About This Sport
From Endurance Grid's Founder
Endurance Grid is here to help you understand the sport, decide if it's the right fit, and learn how to prepare. For course distances, logistics, and race-day specifics, always defer to the race organizer's event page.
With running, there's a distance for every fitness level, a community at every start line, and nothing beats the feeling of crossing a finish line you trained for.
Running is an endurance sport that rewards consistency, and showing up every week compounds in ways that will surprise you.
Running
From 5K to marathon, running races are the most accessible entry point into endurance sport. There's a distance for every fitness level and a community at every start line.
Coming Up
More running races in MA
Frequently Asked Questions (FAQs)
- What is the 4K Trail Run?
- 4K Trail Run is a running event held in Boston, MA. Learn more about the different endurance sports here.
- When and where is the 4K Trail Run?
- Wednesday, May 20, 2026 in Boston, MA at Cathleen Stone Island, Boston, MA. Check the official event page for exact start times and wave schedules.
- How do I register for the 4K Trail Run?
- Registration is handled through their official registration page. Confirm pricing, distances available, and sign up there.
4K Trail Run
May 20, 2026