Diamond Mountain Triathlon logo
Triathlon

Diamond Mountain Triathlon

Date
September 20, 2026
Distance
Adult Triathlon (0.5mi/15mi/2mi) · Adult Duathlon (2mi/15mi/2mi) · Junior Triathlon (0.5mi/15mi/2mi) & more
Register →

From the Organizer

Welcome to Diamond Mountain Triathlon,

hosted in the scenic heart of Harriman State Park. The course features a calm lake swim, a rolling 15-mile bike loop with spectacular views, and a fun lakeside run to the finish. The event is beginner-friendly while still rewarding strong competitors.

Rain or shine, we race — and we’re excited to share the course with you.

What the event offers:
Relaxed and convenient midday start
Police-controlled intersections
Course signage and volunteer support
Race photographers
Free public parking
Junior athletes race Duathlon with adults for free
Junior athletes race Triathlon for free and may have a separate start
Finisher medals for all participants
Awards for Top-3 Men & Women in both Triathlon and Duathlon

Overall Adult Triathlon Winners are getting champion suit:

Free jersey for Triathlon participants:

Duathlon participants are getting running jersey

 

    Follow our race at @Diamond_Mountain_Races

 

Race Schedule
Date: Sunday, September 20
Start Time: 12:00 PM
Cutoff: 2:20 PM
Awards: ~10 minutes after Top-3 Women finish (Triathlon + Duathlon)

Race Location:
Lake Welch Beach
800 Kanawauke Rd, Stony Point, NY 10980
Only the Kanawauke Rd entrance is open before the event (Exit 14 at Palisades Pkwy)

Race course:
Triathlon: 0.5mi swim in Lake Welch. Biking is one 15-mile lap around the park, Strava record is here. 2 mile run, Strava record is here.
Duathlon: Both runs are the same: 2 miles, Strava record is here. Biking is one 15-mile lap around the park, Strava record is here.
Transition at Lake Welch picnic area. See maps on the bottom of the page.

Registration for Triathlon and Duathlon: 
Check-in opens 1 hour before start and closes 20 minutes before start.
Online registration is recommended — it keeps things smooth and helps avoid mistakes at the table.

Bike Race Info:
Interested in the cycling race at the same venue?
Registration for the Diamond Mountain Classic is at:
BikeReg.com/DMC
Note: you can participate only in one race since they're running simultaneously

Race numbers
Jersey number should be placed on the front. Bicycle number goes either on the seat post (more aero) or on the top tube. Helmet number goes on the front. Registration desk has markers to draw a number on the left arm and leg for your swim.

Race results: Draft results will be posted shortly after the last finisher (no later than 2:45 PM).
Official online results (with transition splits) are normally available within 48 hours.

Awards: Top-3 Men and Women for each race get medals and merchandise. Age group awards will be offered if turnout meets minimums. Rest of participants get finisher medals.
Overall Man and Woman triathlon winners get special triathlon suit with race logo as an award.

Photos: will be published within 48 hours at Verrazano Team Facebook page .
9/21/25 Diamond Mountain Triathlon:
By @bikerjun here
By @photovelo.co here

4/27/25 Diamond Mountain Duathlon:
By @bikerjun DM Duathlon, All Podiums
By @photovelo.co here

Swim notes: Wetsuits welcome.
Body marking on the left arm & leg helps timers during swim exit.

Bicycle requirements: Any bike is fine — just make sure it’s in safe working condition and suited for rolling terrain. No rental bikes will be available.

Facilities: 
Free parking
Open restrooms
Water available at check-in
Trash bags provided

About Us: Verrazano Team is a NYC based club organizing multisport and cycling events throughout the city. Our goal is to create safe, well organized, and welcoming races that support local athletes, juniors, and newcomers to multisport.

Events

Adult Triathlon (0.5mi/15mi/2mi)12 PMRegister →
Adult Duathlon (2mi/15mi/2mi)12 PMRegister →
Junior Triathlon (0.5mi/15mi/2mi)12 PMRegister →
Junior Duathlon (2mi/15mi/2mi)12 PMRegister →

Weather

Typical Conditions

It's too far out for a forecast, so here's what weather on this date is normally like in the area. A race day forecast will replace this as race week approaches.

Typical High

73°

Typical Low

50°

Chance of Rain

30%

Based on US Climate Normals data from Yorktown Hts 1w, 11 mi from the venue.

Sunrise 6:42 AMSunset 6:59 PMDaylight 12h 16m

Host City

About Stony Point, NY

Elevation

80 ft

Nearest Airport

HPN

Westchester County Airport · 19 mi

Major Hub

LGA

LaGuardia Airport · 32 mi

Time Zone

Eastern Time

From Endurance Grid

Line up lodging and travel early to lock in your race weekend.

Race Location

Your Next Start Line

What Are You
Waiting For?

Every finish line starts with a single decision. Claim your spot at Diamond Mountain Triathlon, put it on the calendar, and turn “someday” into a start date.

104

Days to train

Race
Diamond Mountain Triathlon
Date
September 20, 2026

From Endurance Grid

About This Sport

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.

Three sports, one race — swim, bike, run in sequence, with transitions that are a discipline of their own.

Open water, open roads, and competition with yourself. Cross the finish line knowing what it took to get there.

Read the Guide

Triathlon

Swim, bike, run — back to back. The sprint distance makes it far more accessible than most people think.

Frequently Asked Questions (FAQs)

What is the Diamond Mountain Triathlon?
Diamond Mountain Triathlon is a triathlon race held in Stony Point, New York on September 20, 2026. It is one of the many endurance events listed on Endurance Grid, a multi-sport endurance event calendar covering running races, triathlons, HYROX, and more endurance sports across the United States. Find more triathlon races near you or explore our sports guides to learn what race day actually feels like.
When and where is the Diamond Mountain Triathlon?
Sunday, September 20, 2026 in Stony Point, New York at 800 Kanawauke Rd, Stony Point, NY. Check the event page for exact start times and wave schedules.
How do I register for the Diamond Mountain Triathlon?
Registration is handled through the event's registration page. Confirm pricing and distances there, and sign up.

Diamond Mountain Triathlon

Sep 20, 2026

Register →