This 101 Freeway Overpass Could Keep Mountain Lions From Being Roadkill

A proposed bridge could help bobcats, mountain loins and other wildlife safely cross the 101 freeway.

The massive freeway overpass—which would span the 101 near Agoura Hills if approved—would offer safe passage for the animals and reduce the risk of them getting hit while trying to cross the busy freeway, reports the L.A. Times. The bridge would offer a 165-foot-wide, 200-foot-long landscaped passageway near Liberty Canyon Road, connecting the Santa Monica Mountains to the south with the Simi Hills and Santa Susana Mountains. The passageway would also help to protect motorists who are sometimes hurt or killed in collisions with the animals.

State agencies, wildlife agencies and elected officials have all endorsed the proposed passageway—which would be the largest like it in the country—and now Caltrans has finished a study concluding that the sprawling bridge could actually be built. That is, assuming funding can be achieved. "It's critically important to provide a safe crossing over the busy 101 Freeway for wildlife," according to state Sen. Fran Pavley (D-Agoura Hills), who lives near the proposed bridge. "Now we need local, regional and national financial backing."

The study, conducted by Caltrans for the ambitious project, was just released yesterday by the Mountains Recreation and Conservation Authority. The projected cost for the bridge is estimated between $33 million to $38 million, and supporters say they would likely seek public funding for the majority of it. The bridge would also be accessible to hikers, mountain bikers and equestrian crossings. Currently, the only option for wildlife crossing in the area is a narrow tunnel beneath the 101 near Liberty Canyon Road, but animals don't always use the passageway, according to The Acorn.

For years, mountain lions and other animals—particularly large ones—have been threatened by the dangerous and imposing barrier of the 101 and other freeways that divide once-continuous habitats. While a few have managed to successfully—and remarkably—cross the freeways that crisscross L.A., others have not been so lucky. Since 2002, when National Park Service biologists began researching mountain lions in the area, drivers have struck and killed a dozen large cats trying to cross the freeway. According to the National Park Service, cars are one of the biggest threats to the animals around Los Angeles.

Freeways and expanding urbanization have also led to other problems that threaten Southern California's mountain lion population, including sometimes deadly fights over territory and inbreeding due to a limited gene pool. Supporters of the freeway overpass believe that the passageway could help protect wildlife and enable them to expand their habitat.

Similar wildlife overpasses and underpasses have had success elsewhere as well, including the Flathead Indian Reservation in Montana, where around 30 species have been observed crossing bridges over 20,000 times per year. Washington state just began construction of a 150-foot bridge that would help black bears, cougars, deer, elk and even small wildlife cross Interstate 90 near Snoqualmie Pass. Other structures have been built throughout Canada, Europe and Africa to help wildlife migrate.

The Caltrans report is the first step towards a final design and the next step will be creating an environmental document, which will be funded by a $1 million grant from the State Coastal Conservancy. During that period—which will last until 2017 —the public will be asked to weigh in on the project.