Boulder County government offices are closed Wednesday, June 19, in observance of Juneteenth. Primary Elections Vote Center locations are open.

Park & Trail Hours
Carolyn Holmberg Preserve

Park & Trail Hours

Parks, trails, and open space areas are open from sunrise to sunset. Parking at trailheads after sunset and before sunrise may result in a fine.

Plan Your Visit

  • Know when sunrise and sunset occur. Check your mobile device, or the graphic below, for exact times.
  • Park officials use sunrise and sunset times to determine if visitors are violating park hours.
  • If your car is parked at a trailhead after official sunset or before official sunrise times, you are in violation of Boulder County Parks & Open Space regulations and may receive a ticket.

Enjoy Open Space During Daylight

The twilight hours after sunset and before dawn are critical times when many wildlife hunt, forage, and breed.

The presence of humans (and their noise and lights) disrupts those activities at night that are so important to the well-being of wildlife.

Daylight visits have the least impact to nature. Protect wildlife by being in the park only after sunrise and leave before sunset. Learn more about nocturnal animals in Boulder County.

If you cannot see the sun, stay out of the park.



The following trails are considered commuter trails and are open 24 hours per day. Trailheads close at sunset and parking is not allowed between sunset and sunrise.

  • Longmont-to-Boulder (LoBo) Trail
  • Coalton Trail
  • Coal Creek Trail
  • Rock Creek Trail
  • Meadowlark Trail
  • US 36 Bikeway
  • Boulder Canyon Trail
  • Open Sky Loop trail adjacent to Pike Road
  • Mayhoffer-Singletree Trail
  • Neighborhood connecting spurs

Contact Us

Parks & Open Space

8 a.m. to 4:30 p.m.

Office Location

5201 St. Vrain Road
Longmont, CO 80503
Map and Directions
Office Hours: 8 a.m. to 4:30 p.m.
Friday by phone, email, or appointment only.

Parks are open sunrise to sunset