Project Fact Sheet
Project Purpose: The purpose of the project is to reopen and restore full access to the section of State Route 140, which was damaged by the Ferguson rockslide. Currently, motorists use a temporary bypass route to travel this portion of State Route 140. Restoration of State Route 140 would eliminate inconvenient detours or extended commute times for residents, businesses, and workers in the area. Restoration of the route would also give travelers a direct route to Yosemite National Park and other destinations along State Route 140. Eight build alternatives and one no-build alternative are being considered.
Project Description: The California Department of Transportation (Caltrans), as assigned by the Federal Highway Administration propose to permanently restore the section of State Route 140 that was damaged by the Ferguson rockslide.
The following alternatives are being considered:
Alternative C: Realign the highway to the northeast, spanning the Merced River and bypassing the rockslide. The highway would cut through the mountain across from the rockslide and then span back across the river where it would meet the existing alignment. Two bridges would be constructed across the river.
Alternative T: Realign the highway to the northeast, spanning the Merced River and bypassing the rockslide. The highway would tunnel through the mountain across from the rockslide and then span back across the river where it would meet the existing alignment. Two bridges would be constructed across the river.
Alternative T-3: Construct a tunnel on a new alignment, tunneling into the west canyon wall, under the rockslide, and realigning with the existing highway.
Alternative S: Realign the highway to the northeast, spanning the Merced River with two bridges and bypassing the rockslide with a hillside viaduct.
Alternative S-2: Realign the highway to the northeast, spanning the Merced River with two steel truss bridges, or tied arch bridges, and bypassing the rockslide with a hillside viaduct.
Alternative R: Construct a rockshed through the rockfall debris (talus) and restore State Route 140 on the existing alignment.
No Build: State Route 140 would remain damaged and blocked by the rockslide. Temporary bridges will remain in place. This alternative would not meet the Purpose (restore full use of SR 140) and Need (restore safety, security, and welfare of communities affected by the slide) of the project.
Cost: Construction costs for the alternatives range from $18 million to $378 million
Funding Source: Federally funded through the Major Damage Permanent Restoration Program.
Project Timeline:
April 2006
Rockslide activity began within the Merced River Canyon on April 29.
May 2006
On May 28, a major rockslide covered approximately 600 feet of the highway. As a result, State Route 140 was closed to traffic from 8 miles east of Briceburg to 7.6 miles west of El Portal. The closure of the highway created severe hardships for residents and businesses in the area.
June 2006
A State of Emergency in Mariposa County was declared that expedited work on a temporary highway detour around the rockslide.
August 2006
The emergency detour project erected two bridges across the Merced River to temporarily divert traffic on State Route 140 around the Ferguson rockslide until a permanent solution could be developed and built.
During 2007
The existing temporary bridges prohibit vehicles over 28-feet in length from crossing and using the State Route 140 detour. As tour buses are included in this restriction, Mariposa County continued to suffer economically due to a loss in tourism revenue.
Environmental process for the permanent restoration project was underway. Alternatives were developed and multiple studies were performed to analyze the affects of those alternatives on the environment.
November 2007
Draft Environmental Document (Initial Study/Environmental Assessment) was circulated for public review.
January 2008
Comment period for the draft environmental document is concluded. Comments received indicated that the project could have a significant effect on the Merced River, which is designated as a Wild and Scenic River. Based on those comments, Caltrans begins the process of preparing a draft Environmental Impact Report/Environmental Impact Statement.
Early 2008
Based on cooperating agencies’ input and the need to minimize any effects on the Merced River, new alternatives were developed and additional studies were initiated. The additional studies include a river geomorphology study, a recreational survey, a noise/bioacoustics study, and an updated visual impact assessment.
April 2008
Original emergency declaration is amended. Caltrans along with cooperating agencies prepare environmental documentation to modify the existing temporary bridges and remedy the vehicle length restriction, thereby reopening the highway to all essential traffic.
May 2008
Construction of new temporary bridges begins.
July 2008
Construction on the new bridges ends. The new detour was opened to all traffic on June 27, 2008.
November 15, 2010
Begin public circulation of Draft Environmental Impact Statement/Environmental Impact Report.
January 13, 2011
End public circulation of DEIS/EIR.