If you commute the 101 through Liberty Canyon, you already know the shape of it. A concrete deck arcs over ten lanes just west of the Chesebro exit, its sound walls dark against the chaparral, its top surface a bare tan platform that has looked more or less the same for months. That is about to change quickly. Between now and early December, crews are laying in the living cover that turns a bridge into a piece of habitat, and the whole project shifts from something you drive under to something you drive under and no longer notice.
That last part is the point. The crossing was never designed as a landmark for people. It was designed to disappear into the hillside on both sides so a bobcat will use it without hesitating. For residents who have watched this thing get built for four and a half years, fall 2026 is the last window to see it as a construction project rather than as permanent scenery.
December 2 Is the Date
The Wallis Annenberg Wildlife Crossing is scheduled to open on December 2, 2026, creating a safe passage for mountain lions over the 101 Freeway. Project leaders announced the date at an Earth Day 2026 press conference, four and a half years after ground broke on the site.
The structure will be the largest wildlife crossing of its kind in the world when it opens. Governor Newsom's office frames it as protecting Los Angeles' native wildlife and over 300,000 drivers daily, which is the honest scale of the traffic passing beneath it every day. The species the crossing is built for — mountain lions, bobcats, gray foxes, coyotes, mule deer — have been genetically isolated in the Santa Monica Mountains for decades because the freeway sits directly across their range.
The Planting Is the Story Right Now
The visible work between August and the ribbon-cutting is horticultural, not structural. In April, Caltrans and partners placed 6,000 cubic yards of living soil across the bridge structure in preparation for planting this fall, which will include over 50 native species and restore wildlife habitat both on the crossing and in surrounding open-space areas.
Approximately 5,000 native plants will be installed atop the bridge, scheduled for completion in fall 2026. The collection includes coastal sage scrub species such as California aster, a source of pollen and nectar for bees; purple sage, which attracts hummingbirds; hoaryleaf ceanothus, which acts as a shelter for small wildlife; narrowleaf milkweed that is critical to the survival of monarch butterflies; bush sunflowers and scarlet bugler. The new habitat will support the movement of native species like mountain lions, bobcats, deer, foxes and pollinators while reducing wildlife-vehicle collisions and the genetic isolation caused by freeways.
If you have walked any of the trails off Cheseboro Road or Las Virgenes, most of those species will look familiar. That is intentional. The bridge is being planted to match the biome on either side so the animals crossing it read the surface as continuous hillside rather than as a novel structure. A partial list of what to expect on top:
- California aster
- Purple sage
- Hoaryleaf ceanothus
- Narrowleaf milkweed
- Bush sunflower
- Scarlet bugler
Beth Pratt, the National Wildlife Federation's California regional director, told KNX News that pollinators have already arrived ahead of the four-legged users. "I've recorded multiple species of butterflies up here," she said of visits to the completed deck this spring.
What Agoura Road Drivers Should Expect Between Now and Ribbon-Cutting
The structure over the 101 was the visually dramatic phase. The current phase is the harder one. Although the structure over the freeway is larger than the one being built over Agoura Road, officials said the final phase of construction is much more complex. It spans a smaller two-lane local road, but is as wide as the structure over the freeway and requires a more extensive foundation.
Translation for anyone whose daily route touches Agoura Road between Liberty Canyon and Chesebro: expect the construction footprint to stay noticeable through late fall. Phase two, the final phase in the construction of the Wallis Annenberg Wildlife Crossing, will create the connecting structure over Agoura Road and restore habitat to protect natural water flowlines and heritage oak trees near US 101. Utility relocation along the freeway corridor is part of that same push and involves coordination across several agencies.
Freeway lanes in both directions will remain open during the day through most of the duration of the project. Some lanes will be closed at night. Detours will be provided as needed. If you have a standing evening drive that uses that stretch, the practical move is to check Caltrans District 7 alerts before you leave the house on weeknights this fall.
How to Actually See It Before It Opens
The crossing is not a public park and will not be a pedestrian walkway after it opens. The habitat only works if humans stay off it. That is why the only way to walk on the bridge is through the docent-led tours the #SaveLACougars campaign has been running by reservation, aimed at giving residents a look at the deck and the plantings before the site is closed to foot traffic permanently.
If tours are not your speed, Caltrans and the National Wildlife Federation have kept a webcam trained on the bridge that runs in real time. It is the easiest way to watch the fall planting unfold without leaving the house. For anyone who has followed the project since the Earth Day 2022 groundbreaking, the coming ten weeks are the visual payoff.
Why This Took So Long and Cost So Much
Cost overruns and delays are worth a paragraph because they have shaped local conversation about the project. After cost overruns and delays pushed back the project by at least a year, the world's largest wildlife bridge finally has a ribbon-cutting date. Project leaders have been direct about the drivers.
Near-record rainfall saturated the construction site in 2023 and 2024, delaying work. Inflation, labor shortages and the sheer complexity of the project also pushed costs higher. By early 2026, the construction project was $21 million over budget due to a variety of factors. Project managers and public advocates for the project stated that it was delayed, first citing record rainfall in the 2022–2023 California floods, which interrupted ground-compaction work which had to be redone in 2023, and then subsequently after the February 2024 California atmospheric rivers event. In February 2026, the state committed an additional $18 million from the general fund to finish the work.
The reason to name those numbers is not to relitigate the budget. It is to explain why a project that looked visually complete a year ago is only now approaching a ribbon-cutting. Building a functioning ecosystem on top of ten lanes of freeway is not the same engineering task as pouring the deck itself, and the last twelve months of work reflect that.
What Changes for the Neighborhood After December 2
Once the crossing opens, most residents will experience the change as an absence rather than a presence. The construction trucks stop. The Agoura Road detours end. The daytime lane closures on the 101 disappear. Within a season or two, the deck itself will visually merge with the hillsides on either side, and the bridge will read as a continuation of the terrain from the driver's seat.
The longer-term shift is quieter. Wildlife crossings elsewhere in North America have measurably reduced vehicle-animal collisions on the roads they span. Reconnecting the Santa Monica Mountains to the Simi Hills gives the mountain lion population a genetic future that biologists have argued for decades it does not currently have. Deer, bobcats, coyotes, and pollinators are all expected to use the crossing in higher numbers than lions, which are the marquee species but also the rarest.
For anyone whose sense of Agoura Hills is bound up with the open space that borders it, the crossing is worth a specific kind of attention this fall. Not the ribbon-cutting itself, which will be crowded and short. The two months before it, when the plants go in and the deck starts to look like the hillside it will eventually become. That transition is the version most residents will remember.
If you are thinking through a move within Agoura Hills, weighing a downsize, or curious what a hillside home near the open-space corridor is worth in this market, Happy SoCal Homes works this side of the Conejo Valley every day. Schedule your free consultation and we will talk through what is actually happening on your block, not just on the freeway.
