3952 Butterfield Crossing Dr, Castle Rock, CO 80109, USA


3952 Butterfield Crossing Dr, Castle Rock, CO 80109, USA



We welcome you to our 18th annual youth triathlon! Tri the Rock is designed for, and open to youth ages 5 to 18. Come for a great day of fun, food, prizes and sport!

Age division participants for Tri the Rock compete based on age on RACE DAY. Be sure to register and prepare accordingly. We are happy to be moving Tri the Rock back to Butterfield park this year!


Early registration fee now active!! Price increase after June 1st!

Race Distances (by age category)

15-18 years

  • 200 meter swim (eight pool lengths, down and back four times)
  • 16 kilometer bike ride
  • 3 mile run

11/12 years & 13/14 years

  • 100 meter swim (four pool lengths, down and back twice)
  • 8 kilometer bike ride
  • 2 kilometer run

7/8 years & 9/10 years

  • 50 meter swim (two pool lengths, down and back)
  • 4 kilometer bike ride
  • 1 kilometer run

 5/6 years

  • 20 meter swim (one pool width)
  • 1 kilometer bike ride (one lap around Butterfield Park)
  • 500 meter run (small loop within Butterfield Park)



You DO NOT need a USAT number to participate in Tri the Rock.


  • 15-18 year olds begin at 7:30 am; the rest of the age groups will follow in order of oldest to youngest.
  • 5/6 year olds begin at approximately 10:30 am (once all of the other age groups are complete and the course is clear, times are estimated)

Packet Pick Up (REQUIRED):


      RNK Running & Walking

    440 4th St., Castle Rock

   Packet Pickup will be annouced at a later date

Important Protocol Reminders

  • Safety for athletes, staff, and volunteers will continue to be our top priority.  Current social distancing measures will be in effect.  
  • Bike transition area for ages 7 & up will be located at the larger parking lot northwest of pool area. Ages 5 & 6 transition area will be north of the pool.
  • Staff will not be assisting swimmers in the pool. If parents anticipate that their child may need assistance, parents are encouraged to be in the pool with their child (these will be the ONLY parents allowed in the pool area). If a child has an unexpected challenge in the pool, our staff will jump in and remove the child, resulting in DNF for the swim portion.  The child may then continue to the transition area to complete the other disciplines of the race.

Free Informational Clinic on Sunday, Sept 3 beginning at 1 p.m.

First time competing at Tri the Rock? Join us for the FREE clinic at Castle Rock Rec Center (Panorama Hall) We will meet at buttfield park to learn all the ins and outs of this triathlon. Registration is required and space is limited.

*Packets will be available for clinic attendees.

Can't make the clinic? Please load and review the clinic information.