When you try to build a mountain on one of the busiest highways in the country, it’s easy to envy the original creative story, and the natural space is simply formed with a wave of hands.
In these stories, there are no buried overhead wires to move. There are no vehicles that can be transferred, there are stable underground streams, majestic oaks that must be preserved or soils that need to be inoculated with local microorganisms.
But it is an imminent challenge for Wallis Annenberg Wildlife Crossing designers and builders, the largest and most ambitious crossing in the world, designed to emulate wildlife on 10 Lane 101 Freeway in Agoura Hills.
The crossover structure itself is mostly done – except that planting will happen this fall – but it is basically a bridge, now with nowhere to go, crouching on the highway outside the Freedom Canyon Drive. (Although – News flash! – Even though it has no connection to nearby hills, the first non-invasive wildlife was found on the bridge last week: the Western fence lizard basking in the sun on the top, about 75 feet above the traffic below.)
The second and final stage is the installation of the connector-the shoulder of the structure that will allow the freeway debris to easily cross the San San Sanaana Mountains in the north and the Santa Monica Mountains in the south.
Expanding areas where wildlife can safely roam will increase opportunities for finding a partner, while improving the health and genetic diversity of mountain lions, such as P-22, such as P-22, whose solitary life in Griffith Park helps inspire crossings.
The second phase is the toughest part of the project, especially the southern side connection of Agoura Road, said Robert Rock, CEO of Chicago-based Rock Design Associates.
Wallis Annenberg’s wildlife cross connector will be supported by a tunnel on Agoura Road, which will be roughly between two white trailers in the photo, and then thread (as much as possible) around the mature oak grove into Santa Monica Mountains.
(Jeanette Marantos)
Work on the south side requires burying overhead wires near the site, moving water lines for the Las Virgenes Municipal Water District, stabilizing an underground creek (dubbed No-Name Creek) that runs under the tunnel site to prevent erasion and then driving two walls of pipelines deep into the ground for 175 feet along Agoura Road to build the 54-foot-wide tunnel that will span the road.
Once the tunnel is built and poured into the concrete roof, the workers will actually move a small piece of soil from the north side of the highway, and when section 101 was built in the 1950s it will accumulate there to cover the tunnel and create a sloping shoulder that connects the shoulder to the Santa Monica Mountains.
The final work will be to plant more native shrubs, perennials and trees on the shoulders and add two miles of galvanized steel fences on either side of the intersection to keep the animals above the intersection and away from artificial roads and houses.
Relaxed furry, right? Apart from one detail, they have to do all these buildings and the earth’s movements without disturbing the local oak jungle growing on site.
The designer planned to walk through the grove of mature oak on either side of Agoura Road to preserve as many mature trees as possible, when crossing the road was built at the intersection on the road and entering the Santa Monica Mountains.
(Christina House / Los Angeles Times)
“It’s a tricky pocket,” Locke said. “We definitely need to thread the needle.”
He said some smaller trees may have to be removed, but designers are doing everything they can to maintain local trees growing on site. Not surprisingly, because the entire project focuses on the foundation of concrete and steel to recreate the properties as much as possible, while native plants grow from seeds collected within the three-mile radius of the project, while local fungi and microorganisms are specially inoculated into the soil to enhance their growth. The plants are tilting at the project of a nursery several miles from the site.
Locke said Valencia contractor CA Rasmussen Inc., which established the first phase of the project, also won the bid for the second phase. The weather delay – mainly from heavy rains in 2022 and 2023 – pushes Crossing’s final completion date to the end of 2026. California offers $58.1 million of its $92.6 million program as part of its “30 x 30” goal to protect 30% of the state and 2030 private campaigns.
The final phase of work is expected to begin next week. Most of the preparations and tunnel construction will require at least partial closure of Agoura Road, but builders must issue a 30-day notice before the closure begins.
The artist’s renderings show how the tunnels of Agoura Road and Wallis Annenberg Wildlife Crossing look southward towards the Santa Monica Mountains, when the intersection was completed by the end of 2026. The highest view is facing east of Agoura Road, and the bottom view looks west.
(Rock Design Partners and National Wildlife Federation)
(Rock Design Partners and National Wildlife Federation)
A specific closure time is still in talks with Agoura Hills, but Rock said he expects Agoura Road to be partially closed during the day only during the day while the contractor is working. He said the closures are expected to start in early August and last “a few months.”
“I really can’t say it [how long] He said after a few months of value, I hope we can finish by the end of the year. ”
From the spring, special cover crops with four native plants have begun to grow on the main structure.Eriophyllum Confertiflorum)California Poppy (Eschscholzia California),,,,, Giant Wang De (Elymus Condensatus) and Santa Barbara Milk vetch (Astora Sumatrichopodus)The choice is because they are best thrived with mycorrhizal fungi and other microorganisms added to the soil.
Last week, at least one invasive black mustard plant could also be seen at the intersection – which is not surprising, as the surrounding hills are lush with the fast growing, easily spreading mustard sauce earlier this spring – but contractors should have these invasive plants to give locals a chance to build.
Hundreds of native plants that will be planted in nurseries near the project this fall, probably in October, may be October, said Beth Pratt, California Regional Executive Director of the California National Wildlife Federation.
The tops of Wallis Annenberg wildlife now resemble the red Horse Hill, although people sowed the seeds this spring sowed the native plants of the mulch, namely California poppy, giant wild rye, Santa Barbara milk vetch and golden fruit. In October, hundreds of larger native shrubs and perennials will be planted at the intersection in October, which will be grown from nurseries near the project.
(Christina House / Los Angeles Times)
Save La Cougars sells a mixture of six native seeds from Pacific Coast Seed (formerly S&S seeds) to brag for those who wish to brag about the right to grow six native plants that will excel at the intersection (common dew)Acmispon Glaber var. glaber)gray buckwheat (eriogonum cinereum), Showy Penstemon(Penstemon Spectabilis)black sage (Salvia Mellifera)narrow leaf milkweed (asclepias fascicularis) and foothills acupuncture grass (stipa lepida)
You can order a pack of souvenirs online for $10. The proceeds will support the nursery for the project, which is presented in the new Save La Cougars video, which explains how to select and cultivate all cross-over native plants, soil and compost.
Meanwhile, recent tariffs have increased new funding issues for the project. Pratt said it was unclear whether the project would need to do more fundraising to cover all the added costs.
Robert [Rock] Caltrans has been redesigning and value design around the clock to reduce costs, which is why we can continue [with Stage 2]Pratt said. Teamwork is extraordinary. ”
They may need to raise more money to cover the final expenses, such as the two-mile high fence estimated by the rock, which will cost about $2 million, but now, Pratt says, the design adjustment appears to include additional costs. “They let them down again, so I think we have time.”
Meanwhile, while all these human problems are developing, even though the bare terrain now looks like the moon, Western fence lizards seem to be inhabiting at the unfinished intersection. When Pratt spotted the small reptile, she led a small group of tourists and she took a little time to process its imports.
“I’ve been seeing Western fence lizards in my yard, and they’re everywhere – one of the most common animals you’ll see in California.” “But then hit me, ‘Wait. This lizard is on the bridge!!! This is the first animal I’ve seen on the bridge!!! I stopped the group… and told them – “You’re seeing the first animal on the cross.” Everyone cheered.
