Wildlife crossing's supporters mark construction progress on 101 Freeway in Agoura Hills

AGOURA HILLS, Calif. (KABC) -- Supporters of the Wallis Annenberg Wildlife Crossing gathered to celebrate the ongoing construction of the project on Earth Day.

The crossing aims to provide connection between the population of mountain lions and other wildlife to the larger and more genetically diverse populations to the north.

"We would not have mountain lions here. We probably wouldn't have a lot of wildlife here in the future if we don't do this, so for me it became a moral imperative," said Beth Pratt, Executive Director of the National Wildlife Federation. "Knowing that we actually did save this population, that feels pretty good."

The crossing will be one of the largest crossings of its kind in the world, set to stretch 210 feet over ten lanes of the 101 freeway.

The closures are necessary for crews to lift and install large concrete beams, or girders, over the freeway. Each of the girders weighs between 126 and 140 tons.

"Without connectivity to the mountains north of the freeway here, that can lead to very close inbreeding and low genetic diversity and that's exactly what we've been seeing," wildlife biologist Jeff Sikich said.

For almost 20 years, researchers have been looking into the crossing, which has been one of the biggest threats in the area according to Sikich.

"Without connectivity to the mountains north of the freeway here, that can lead to very close inbreeding and low genetic diversity and that's exactly what we've been seeing," Sikich said. "So I like to say this crossing could not have come at a better time. It's going to help save our local mountain lion population and also help the diversity of wildlife in the region."

As crews continue their nightly work on the overpass, community groups are marking the considerable progress they've made so far.

"We're celebrating what has been another unique milestone in seeing the precast box girders' get placed over top the freeway," president and CEO of rock design associates Robert Rock said. "For the longest time everybody could see the structures growing out of the ground, but this is the first time that people are driving underneath it which is really exciting to start and see that take shape."

Construction crews have installed about 10 of the 82 girders.

The phase of the project, with the closure every night, is expected to take up to 45 days.