This work is 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 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. The project 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 management best 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 2026

  • Continued repairs along the East Ridge and Mount Sanitas corridors.
  • Restoration of damaged areas due heavy use by closing social trails, reshaping slopes and replanting native vegetation.
  • Designation of a half-mile section of the Cairn Trail with official neighborhood access points at Linden Ave. and 4th St.
  • Restoration of informal trails to reduce habitat fragmentation and wayfinding confusion.
  • Continued improvements in bouldering areas.

Completed in 2025

Staff and partners completed more than 3,100 hours of on-the-ground work in 2025

  • Summit Approach Repairs
    Crews worked on trail segments approximately 1,000 feet below the summit on both the Mount Sanitas Trail and the East Ridge Trail. Work includes building new stone structures, repairing trail surfaces and restoring areas damaged by erosion - replacing outdated infrastructure to make trails safer and more sustainable.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 Boulder Climbing Community, improvements were made to bouldering sites located along the Mount Sanitas Trail. These enhancements included creating designated access points, 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 included the closure and restoration of informal trails that duplicate main routes. This work improves wayfinding, reduces noxious weed spread and enhances 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.