• Natural Lands
  • Hiking Trails
  • Fishing
  • Boating
  • Grill
  • Picnic Area
  • Playground
  • Restroom
  • Water Access


The Boulder Reservoir will be hosting the 2021 Ironman 70.3 Triathlon Aug 2-7.

Begins Thursday August 5th at noon until Saturday August 7th:
Boulder Reservoir will be closed to everyone except those with an Ironman access pass.

Saturday August 7th 4:00 a.m. to 2:00 p.m. 51st Street will be closed to all traffic except residents, city staff and Ironman staff.
Saturday August 7th 4:00 a.m. to 5:00 p.m. Coot Lake parking area and 55th St trailhead will be closed.

For more information about the event

Boulder Reservoir will reopen Sunday, August 8 at 7 am.

About the Boulder Reservoir

The Boulder Reservoir is a 700-acre, multi-use recreation and water-storage facility, owned and managed by the City of Boulder and operated as a water supply by the Northern Colorado Water Conservancy District. It is used for recreation, drinking water and irrigation. Popular recreation activities at the reservoir include boating, swimming, sun bathing, water skiing, fishing, picnicking, walking, running, cycling and wildlife viewing.

Parks & Recreation Master Plan Update