Ten Lanes, and a Date in December

A concrete bridge already sits over ten lanes of the 101 Freeway in Agoura Hills. The animals it was built for have not been invited across it yet.

The Los Angeles Times, on 8 October 2026, said the Wallis Annenberg Wildlife Crossing is on track to open on 2 December, if a heavy winter storm does not stop the soil work. USA Today printed the same date on 13 October. LAmag printed it on 9 October. The project and those papers call it the world's largest wildlife crossing. It is 210 feet long. LAmag also printed a width of 174 feet. The budget is about 114 million dollars, up from 92 million. Yahoo, citing the same reporting, put the increase down to inflation, construction complexity and labour shortages.

The freeway span has had its deck for more than a year. What finished in the first week of October was the concrete deck of the second span, the one over Agoura Road. Crews moved power lines and a water main to get there, and they drilled piles about 75 feet deep without taking out two creeks or a stand of heritage oaks. The Times said 6,000 native plants are already in the soil on the freeway span. What is left is haulage: millions of cubic feet of soil, compacted, between the two structures. Clay and a flood do not compact. That is the El Niño clause. Light rain is fine. A slick site shuts the job.

USA Today quoted a project partner, Pratt, calling it four jobs in one: two structures, a utility relocation, and 13 acres of habitat, beside one of the busiest roads in the country. Coyotes and bobcats have already been seen near the site while the crews are still there. The animal the bridge is for is the mountain lion in the Santa Monica Mountains, cut off from the Simi Hills and the cats beyond, and inbreeding because of it. A sighting of a bobcat beside a worksite is not a lion on the new ground.

A second claim is in the same month. 9News in Colorado said the Greenland wildlife overpass on I-25 near Larkspur, finished this month, is the largest in North America: 200 feet wide, 209 feet long, over six lanes, reconnecting 39,000 acres. The Los Angeles project is longer in one telling and narrower in another. "World's largest" and "North America's largest" cannot both be a settled tape measure. We will say what each outlet says, and we will not referee it.

Key Facts & Figures

• Wallis Annenberg Wildlife Crossing, Agoura Hills, over the US 101
• Opening date printed by the Los Angeles Times, USA Today and LAmag: 2 December 2026, weather permitting
• 210 feet long, over 10 lanes. LAmag: also 174 feet wide
• About 114 million dollars, up from 92 million
• Second deck, over Agoura Road, completed in the first week of October 2026
• 6,000 native plants already in on the freeway span (Los Angeles Times)
• 13 acres of habitat in the project description given to USA Today
• Purpose: reconnect Santa Monica Mountains mountain lions with populations beyond the freeway
• Colorado's I-25 Greenland overpass, finished this month, described by 9News as the largest in North America: 200 feet wide, 209 feet long

Why This Matters

Isolation is a genetic fact, not a mood. A freeway is a wall that cats do not read. A date, a budget and a storm clause are the grown-up version of a ribbon-cutting. The ribbon is in December. The lions are not on the deck.

What We Don't Know Yet

• Whether 2 December holds. The Times was explicit: an El Niño-level storm can slip it.
• Which span is larger, Los Angeles or Larkspur, once width, length and area are all on one page.
• Whether any mountain lion has used the ground. The animals reported near the site are coyotes and bobcats, during construction.
• The final plant list and irrigation. Crews are still hauling soil.

Sources

• Los Angeles Times, 8 October 2026: https://www.latimes.com/environment/story/2026-10-08/wallis-annenberg-wildlife-crossing-is-on-track-to-open-this-winter-unless-el-nino-intervenes
• USA Today, 13 October 2026: https://www.usatoday.com/story/news/state/california/2026/10/13/worlds-largest-wildlife-crossing-near-los-angeles-almost-complete/92239968007/
• LAmag, 9 October 2026: https://lamag.com/animals/worlds-largest-wildlife-crossing-sets-dec-2-opening/
• 9News, Colorado overpass: https://www.9news.com/article/life/animals/north-americas-largest-wildlife-overpass-completed-over-i-25-in-douglas-county/73-e895674f-092a-4cfe-913b-9c883f1e2dac