Boulder plans road closures for Ironman 70.3 on Saturday

DENVER (KDVR) — Boulder’s Ironman 70.3 is returning to the city on Saturday, and while residents are ensured access to their homes during the race, others should be aware of potential delays and detours.

The Boulder half-ironman race, which is a triathlon, will take place at the Boulder Reservoir and the nearby roads, including Monarch Road, Hygiene Road and North Foothills Highway. Access to the course is limited — all athletes and spectators will take a shuttle to reach the race course unless carpooling with a volunteer.

Boulder adds North and Saint Vrain creeks to foothills tubing closures

Here are the biggest takeaways for non-race attendees: Do not try to cross the course. To get to the other side of the bike course, use Highway 36 southbound or northbound on North 75th Street, and Highway 66.

Officials also warn motorists not to attempt to get across the course on Hygiene Road, Niwot Road, Nelson Road, St. Vrain Road, Plateau Road or westbound Jay Road. Those roads will be open for resident access and motorists will experience longer delays than if they use the loop around the bike course, according to officials.

Additionally, when passing bicyclists, motorists should remember to allow at least 3 feet of space between their car and the cyclist. Drivers are allowed to cross a double yellow center line when oncoming traffic is clear to provide cyclists with a safer ride.

Ironman 70.3 Boulder road closures, detours and traffic

The Boulder Reservoir is scheduled to be closed to the public through Saturday, June 8, as it was originally closed for preparation on Thursday. The bike course will be active between 7 a.m. and 2 p.m. and will use the following roads:

  • Highway 119/Diagonal Highway

  • North 63rd Street

  • Monarch Road

  • Jay Road

  • Highway 36/North Foothills Highway

  • H Road

  • North 75th Street/North 73rd Street

  • 71st Street

Highway 119/Diagonal Highway will remain open, but one lane of the Boulder-bound lanes will be closed from North 63rd Street to Jay Road, and delays are expected for motorists on that highway.

  • This is the bike course route for the Ironman 70.3 Boulder scheduled for Saturday, June 8.
    This is the bike course route for the Ironman 70.3 Boulder scheduled for Saturday, June 8.
  • This is the foot race course route for the Ironman 70.3 Boulder scheduled for Saturday, June 8.
    This is the foot race course route for the Ironman 70.3 Boulder scheduled for Saturday, June 8.

Below is an interactive map of the bike course, in addition to road closures and detours around the race.

Boulder also provided the following written road information:

  • Jay Road will be closed to westbound traffic from Highway 119 to 28th Street

  • Highway 36/28th Street will be closed northbound from Jay Road to Hygiene.

  • 75th Street, 73rd Street and 71st Street will be closed southbound from Hygiene Road to Niwot Road

  • Monarch Road will be closed from 55th Street to 71st Street. Residents will be allowed to access their homes via 55th and 63rd Streets.

  • 63rd Street will be closed from Diagonal Highway to Niwot Road from 7 a.m. until 5 p.m.

Through traffic on northbound Highway 36 from Boulder to Lyons can use Highway 119 to Longmont, head north on Hover Road, then west on Highway 66.

See the latest traffic conditions in Denver on FOX31

To get to Estes Park, use the same route or use Highway 119 to Nederland, then north on Highway 72 to Highway 7 and continue north to Estes Park.

Recreational cyclists should also avoid traveling in the same direction as bike course racers.

Copyright 2024 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.

For the latest news, weather, sports, and streaming video, head to FOX31 Denver.