Starting as early as June 9, the City of Boulder will begin important trail improvements in the Mount Sanitas area. This work marks the start of a multi-year project made possible by a $1.1 million grant from the Land and Water Conservation Fund.

Project Overview

This project, identified in the 2011 West Trail Study Area (WTSA) Plan PDF, is the beginning of a multi-year effort that reflects both the City’s commitment to sustainable land management and significant community input. A key priority is preserving Mount Sanitas' historical character and legacy trail footprint while enhancing safety, resilience, and the overall visitor experience.

Mount Sanitas area trails receive nearly 375,000 visits each year, making it one of Boulder's most heavily used natural areas. The trails experience substantial widening, braiding, erosion, and soil loss. OSMP’s focus will be on repairing existing trails and replacing deteriorating infrastructure using durable, natural materials—while maintaining a strong emphasis on sustainable design and ecological best management practices.

Trail work will be completed by Open Space and Mountain Parks (OSMP) trail crews, in collaboration with the American Conservation Experience (ACE), Boulder Climbing Community (BCC), and dedicated volunteer groups.

What to Expect in 2025

  • Summit Approach Repairs
    Crews will be working on trail segments approximately 1,000 feet below the summit on both the Mount Sanitas Trail and the East Ridge Trail. Work will include building new stone structures, repairing trail surfaces, and restoring areas damaged by erosion—replacing outdated infrastructure to make trails safer and more sustainable.
  • Bouldering Area Enhancements
    In partnership with the BCC, improvements will be made to eight bouldering sites located along the Mount Sanitas Trail. These enhancements include creating designated access points, restoring impacted areas, decommissioning social trails, and establishing well-defined zones for crash pad use.
  • Closing Redundant Social Trails
    To protect wildlife habitat and reduce erosion, the project will include the closure and restoration of informal trails that duplicate main routes. This work will improve wayfinding, reduce noxious weed spread, and enhance the overall experience for visitors.

Anticipated Closures and Trail Access

No full trail closures are expected during the first year of work, but intermittent delays may occur. Trail users might be asked to take brief detours or alternate routes to avoid active work zones.

Clear signage will be posted at key access points, including the Mount Sanitas Trailhead, Lion's Lair Trailhead, and the base of East Ridge, to ensure visitors can plan ahead and navigate safely.

Minimizing Construction Impacts

OSMP is trying to secure a temporary parking area for staff during working hours to reduce wear and tear on public access points.