North Fork American River Trail Project

Blackburn Consulting performed this geotechnical/geologic study as part of project EIR preparation and multi-purpose trail design. Proposed project includes over 12 miles of new hiking, biking and equestrian trail along the American River Canyon, involving steep terrain, variable rock conditions and environmentally sensitive slopes. The project extends from the confluence of the North and Middle Forks of the American River (Foresthill Bridge area) to the Ponderosa Way Bridge.

Our geotechnical/geologic study concentrated on:

  • general geologic setting of the proposed trail location
  • evaluation of the feasibility of a sustainable trail
  •  "screening” of geotechnical issues (landslides, erosion hazard, etc.) along the trail alignment
  • identification of trail areas that require specific geotechnical input during construction and options to mitigate these concerns


Significant challenges included access to steep trail locations with dense vegetation and development of reasonable mitigations for trail segments in landslide areas and steep slopes. Our experienced geologists accessed trail locations by hiking in to record significant features using GPS and photographic logging. Working closely with the County and project team members, we developed mitigations such as simple retaining structures (i.e., gabion, rock walls, etc.), avoidance of certain locations, and benching. 


Location Placer County, CA
Agency/Owner Placer County Parks Division
Timeframe 2006 to 2008