Triathlon Calendar near Marlboro 2026-2027

September 2026

Multisport Blue Hills Adventure Race 38 15 12 mi

A USARA-sanctioned, 15 hour adventure race in Greenfield, MA combining biking, trekking, paddling and map navigation for solos and teams.

October 2026

Oct

3

Sa

The Great River Challenge

Northfield | 18 mi from Marlboro

Cross Triathlon Short Course 4 2.5 3.75 mi Solo Triathlon SUP Short... 4 2.5 3.75 mi 2 Person Relay Team Triat... 4 2.5 3.75 mi 3 Person Relay Team Triat... 4 2.5 3.75 mi

Off‑road paddle, run and bike triathlon at Northfield Mountain featuring a mass-start river paddle around Captain Kidd's Island and single track run and bike courses.

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