The Anemone Loop Trail will remain closed from 5 a.m. to 5 p.m., Monday through Friday, while trail work occurs.

The City of Boulder will open the new 3-mile Anemone Loop Trail west of downtown Boulder on Friday, Nov. 19.

Because work is still occurring along the trail, Boulder Open Space and Mountain Parks (OSMP) will open the trail each day after 5 p.m., Monday through Friday, and all day on Saturday and Sunday to help the community enjoy the new 3-mile trail loop. The Anemone Loop Trail will remain closed from 5 a.m. to 5 p.m., Monday through Friday while trail work occurs. When the trail is open, city regulations will require visitors to “stay on trail” and not walk off the path, which creates undesignated, unmaintained trails that can harm sensitive wildlife habitats.

OSMP began construction of the Anemone Loop Trail in May 2020 and anticipates completing construction of the trail in early 2022 – weather permitting. The construction of the Anemone Loop Trail included:

  • Building an “approach trail” that leads to a 2.2-mile loop and two short “spur” trails that provide scenic viewpoints.
  • Constructing 416 stone steps and 1,200 square feet of rock retaining walls to support the trail as it crosses steep, uneven or rocky terrain.
  • Using a helicopter to haul more than 85 tons of rock and building materials to the trail site.

OSMP designed the new Anemone Loop Trail with sustainable trail building principles, which seek to minimize trail erosion over time and limit natural resource impacts that may come from trail construction. These principles include:

  • Designing trail alignments to minimize impacts to help protect wildlife and vegetation, including rare plant species.
  • Constructing trails that gradually ascend with 8 to 10-percent grades, which can significantly reduce trail erosion. Steeper trail grades allow water to gain volume and velocity, which can dramatically increase erosion.
  • Building grade reversals, which are trail segments where a trail will gain elevation, then descend for a few feet and then gain elevation again. This trail feature creates low points in the trail that helps to force water off of the trail at frequent intervals.

The city’s West Trail Study Area Plan called for the construction of the Anemone Loop Trail and OSMP has been planning this project as part of its Capital Improvement Program budgets for several years. The building of the new loop trail also has included the restoration of native vegetation and the closure of undesignated, unmaintained trails to help protect sensitive wildlife habitats.

Visit to view the new trail, which can be accessed from the Centennial or The Peoples’ Crossing trailheads.