In April 2006, a rockslide occurred at Ferguson Ridge in Mariposa County, California. The California Department of Transportation (Caltrans) established one-way traffic along SR 140, resulting in a stall as the prehistoric Ferguson Slide became active and buried the entirety of the route on May 25, 2006. Before the Ferguson Rockslide, SR 140 was a two-lane, undivided highway that connected various Mariposa County communities and provided access for millions of visitors to Yosemite National Park. Restoring two-lane access on SR 140 will eliminate delays for the movement of goods and materials and restore critical community and tourist-travel access.
Caltrans selected this SR 140 project for inclusion within the CMGC pilot program to select a Construction Manager / General Contractor to complete the work. Caltrans recognized both the unique challenges and collaborative efforts required to successfully manage the design and construction of the project. The project scope consists of two major segments of work:
- stabilizing the currently active talus of the slide to allow for the safe uncovering of the existing SR 140 alignment currently under slide material
- constructing a custom “rock shed” structure over the SR 140 alignment at the base of the slide
The rock shed will only be the second structure of its kind in California. It will allow for safe passage of vehicles through the rockslide area and mitigates further closures due to movement of the slide face.