Coamo ran again: San Blas at 61 — the island's most beloved half marathon

On the first weekend of February, Coamo isn't a town: it's a racetrack. The San Blas Half Marathon once again filled the Villa Añeja with runners and the party only this event knows how to throw — 61 editions since 1965, and counting.¹²

The race that put Coamo on the map

San Blas has been run in Coamo since 1965, organized by the Delta Phi Delta fraternity, and is considered among the most important distance-running events in the world.¹² Its 21 kilometers (13.1 miles) have hosted Olympic champions, world-record holders, and the best of boricua distance running — one of the few races on the planet where international stars run in front of a quarter-million spectators in a mountain town.²⁴

San Blas by the numbers

• ~1,500 athletes across international elites, local distance runners, and recreational racers.⁴
• ~250,000 spectators along the route — Coamo's population multiplies by six that weekend.⁴
• 13.1 miles of climbs and descents: the Coamo course is famous for punishing anyone who went out too fast.
• Official and age-group results on the event site and World Athletics.³⁵

More than a race

What makes San Blas unique isn't on the clock: it's the whole town out on the street — improvised grandstands on balconies, music on every corner, neighbors handing out water, and the tradition that in Coamo the last finisher gets the same ovation as the first. For many families it's been an annual date for generations.²⁴

What it means for you

• Want to run it? Registration opens months ahead on the official site; recreational-race slots go fast.¹ Start training hills — the course shows no mercy.
• Going to watch? Arrive early: parking fills by morning and roads into Coamo close in sections. The Coamo hot springs are the perfect post-race stop.
• Local businesses: San Blas weekend is one of the region's strongest of the year for lodging and restaurants — if you run a business nearby, prep early.

What's next

Edition 62 already has a tentative date for the first weekend of February 2027, as tradition dictates.¹ When registration opens and the invited elite field is confirmed, we'll cover it here in the Newsroom.