A permanent fix to the large rockslide covering Highway 140, the major route between Mariposa and Yosemite National Park, could take several years and cost perhaps as much as $100 million, Caltrans officials said Thursday. The agency so far hasn't found a feasible way to repair the road, which was obliterated when the Ferguson Ridge gave way near El Portal in April and covered the highway in several thousand tons of rock. Kome Ajise, director of the Caltrans district that includes Highway 140, has assigned a panel of experts to examine alternatives to the one-lane detour hastily erected around the slide in July. "We're committed to working as expeditiously as possible to find a permanent long-term solution," said Caltrans spokesman Bob Boswell. "The director has been very adamant about us thinking outside the box and developing something as quickly as possible." The hillside gave way about 8 miles west of El Portal on April 29, sending a cascade of shale and dirt tumbling onto Highway 140. Geologists believe two unusually wet winters loosened enough rock to start the slide. No one knows just what a permanent fix might look like, but at this point every possible idea -- up to and including boring a tunnel through the hillside -- is under consideration, Boswell said. Once a formal list of ideas is drawn up, engineers and other experts will assess the cost and feasibility. "The mandate is to look at everything," Boswell said. "We want to be very aggressive on this." Caltrans officials told Mariposa County supervisors this week that the price of fixing the roadway could range from $50 million to $100 million -- a figure Boswell said Thursday is only the roughest of estimates "pulled from the air." Once a solution is determined, Boswell said, a project of this magnitude would normally take two or three years to plan. Caltrans hopes to move much faster than that with Highway 140, he said. The highway is buried beneath a pile of rock stretching some 900 feet up the hillside from the bank of the Merced River, so simply clearing the road is not an option. Although the rockslide does not appear to be moving, some 3 million cubic feet of rock and debris piled above an outcropping above the roadway could give way at any time. "The main rockslide does not appear to be deforming," said Jerry DeGraff, a geologist with the U.S. Forest Service. "But that's a situation that depends upon the weather." DeGraff said a wet winter could cause material already loosened by the slide to come tumbling down or, in a worst-case scenario, further undermine the slope and prompt a much larger rock slide. Geologists hope to learn more when they install three sensors on the hillside next month. The devices will help determine whether the hillside is moving and, if so, in what direction. Two water-level sensors will be installed in the Merced River to indicate whether debris from the slide is impeding the river, he said. The closure of Highway 140 forced commuters between Yosemite National Park and Mariposa to spend hours on circuitous detours on Highways 120 or 41. Caltrans erected two temporary bridges spanning the Merced River on each side of the slide in July. "It's brought life back to normal," said Scott Gredigan, a Yosemite spokesman who lives in El Portal and often travels to Mariposa to run errands. The closure of Highway 140 and resulting detour has had a nominal impact on the park and businesses within El Portal, Gredigan said. Caltrans widened a portion of Highway 120 known as New Priest Grade last month so buses up to 45 feet long could use the road. An average of 398,244 people visited the park each month since April, roughly the same figure recorded during the same period last year, according to park statistics. (SF Chronicle - 9/15/06) Highway 140 Information Caltrans Media Advisory Today’s Date: Monday, September 11, 2006 District: 10 - Stockton Contact: Chantel Miller Phone: (209) 948-7176 FOR IMMEDIATE RELEASE HIGHWAY 140 FERGUSON ROCK SLIDE BYPASS LIMITED TO 28 FOOT TOTAL VEHICLE LENGTH (Mariposa County) The Department of Transportation (Caltrans) opened Highway 140 to 24 hour traffic on September 1, 2006. The two bridge temporary bypass, installed to move motorists around the rock slide, is open to vehicles with a maximum total length of 28 feet, including tow vehicles. This length restriction is strictly enforced due to limited turning radius on the bridges.