Latest news with #P-22
Los Angeles Times
25-06-2025
- General
- Los Angeles Times
The world's largest wildlife crossing is entering Stage 2: What's that mean for traffic?
When you're trying to build a mountain over one of the country's busiest freeways, it's easy to be envious of original creation stories, when natural spaces were formed with just a wave of the hand. In those stories, there were no overhead wires to bury or water lines to move. There weren't vehicles to divert, underground creeks that required stabilization, majestic oaks that had to be saved or soils that required inoculation with local microbes. But such are the looming challenges for the designers and builders of the Wallis Annenberg Wildlife Crossing, the world's largest and most ambitious crossing designed to give wildlife a safe and nature-mimicking passage over the 10-lane 101 Freeway in Agoura Hills. The crossing structure itself is mostly completed — except the planting, which will happen this fall — but it's basically a bridge to nowhere right now, squatting over the freeway just west of the Liberty Canyon Drive offramp. (Although — news flash! — even though it's not connected to the neighboring hills, the first non-insect wildlife was spotted on the bridge last week: a Western fence lizard basking at the top, roughly 75 feet above the traffic below.) The second and final phase is installing the connectors — the structure's shoulders that will permit freeway-fragmented wildlife to easily cross between the Santa Susana Mountains to the north and the Santa Monica Mountains to the south. Expanding the areas where wildlife can safely roam will increase their chances of finding mates while improving the health and genetic diversity of everything from lizards to mountain lions like P-22, whose lonely life in Griffith Park helped inspire the crossing. This second phase is the trickiest part of the project, especially the south-side connection over Agoura Road, according to Robert Rock, chief executive of Chicago-based Rock Design Associates and the landscape architect overseeing the $92.6-million project. 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 erosion and then driving two walls of pilings 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 constructed and the concrete roof is poured, workers will literally be moving a small mountain of soil from the north side of the freeway, where it was piled when this stretch of the 101 was constructed in the 1950s, to cover the tunnel and create the sloping connecting shoulder into the Santa Monica Mountains. The final work will be planting more native shrubs, perennials and trees on the shoulders and adding two miles of galvanized steel fencing on either side of the crossing to funnel animals over the crossing and away from human-made roadways and homes. Easy peasy, right? Except for one more detail — they have to do all this building and earth moving without disturbing a sprawling grove of native oak trees growing around the site. 'It's a tricky pocket,' said Rock. 'We're definitely threading a needle.' Some of the smaller trees may have to be removed, he said, but the designers are doing everything they can to maintain the native trees growing around the site. Not surprising, because the whole project has focused on re-creating nature as much as possible on a foundation of concrete and steel, with native plants grown from seeds collected within a three-mile radius of the project and soil specially inoculated with local fungi and microbes to enhance their growth. The plants are being tended at the project nursery a few miles from the site. C.A. Rasmussen Inc., the Valencia-based contractor who built the first phase of the project, has won the bid to do the second stage as well, said Rock. Weather delays — primarily from heavy rains in 2022 and 2023 — have pushed the crossing's final completion date to the end of 2026. The state of California has provided $58.1 million of the $92.6-million project, as part of its '30 by 30' goal to conserve 30% of the state's lands and coastal waters by 2030. The rest of the funds are coming from private donations. Work on the final phase is expected to begin next week. Much of the prep work and tunnel construction will require at least a partial closure of Agoura Road, but the builders have to give 30-days notice before the closures begin. The specific closure hours are still being negotiated with the city of Agoura Hills, but Rock said he expects Agoura Road will be only partially closed to vehicle and bike traffic during daytime hours, when the contractor will be working. The closures are expected to begin in early August, and last for 'several months,' he said. 'I can't really say [how long] beyond several months' worth of impacts,' he said, 'but I hope we can be done by the end of the year.' A few plants are already beginning to grow on the main structure, from a special cover crop of four native plants hand-sown in the spring — golden yarrow (Eriophyllum confertiflorum), California poppy (Eschscholzia californica), giant wildrye (Elymus condensatus) and Santa Barbara milk vetch (Astragalus trichopodus), chosen because they best flourished with the mycorrhizal fungi and other microbes added to the soil. Last week, at least one invasive black mustard plant was also visible on the crossing — not surprising since the surrounding hills were lush with the fast-growing, easily spread mustard earlier this spring — but contractors are supposed to keep those invasive plants weeded out, Rock said, to give the natives a chance to get established. Hundreds of native plants that were grown from seed in the project's nearby nursery will be planted on the crossing this fall, probably in October, said Beth Pratt, California regional executive director of the National Wildlife Federation and leader of the Save LA Cougars campaign, who is overseeing funding and fundraising for the project. Save LA Cougars is selling a blend of six native seeds provided by Pacific Coast Seed (formerly S&S Seed) for people who want bragging rights to growing six of the native plants that will feature prominently on the crossing — common deerweed (Acmispon glaber var. glaber), ashyleaf buckwheat (Eriogonum cinereum), showy penstemon (Penstemon spectabilis), black sage (Salvia mellifera), narrow leaf milkweed (Asclepias fascicularis) and foothill needlegrass (Stipa lepida) You can order a packet of the souvenir seeds online for $10. Proceeds will support the project's nursery, which is featured in a new Save LA Cougars video explaining how all the crossing's native plants, soils and compost have been chosen and nurtured. In the meantime, the recent tariffs have added a new funding concern for the project. It's not clear yet if the project will need to do more fundraising to cover all the increased costs, Pratt said. 'Robert [Rock] and CalTrans have been working around the clock to redesign and value-design to get the costs down, which is why we're able to proceed [with Stage 2],' Pratt said. 'The team work has been extraordinary.' It's possible they may need to raise more money to cover final expenses like the two miles of extra-tall fencing that Rock estimates will cost around $2 million, but right now, Pratt said, the design adjustments seem to have contained the extra costs. 'They got them down again, so I think we're home free.' Meanwhile, while all these human issues are unfolding, somewhere on top of the unfinished crossing that Western fence lizard appears to be making a home, even though the naked terrain looks like a moonscape right now. Pratt was leading a small group of visitors when she spotted the little reptile, and it took her a moment to process its import. 'I see Western fence lizards all the time in my yard and they are everywhere — one of the most common animals you will see in California,' Pratt wrote in an email. 'But then it hit me, 'Wait. This lizard is on the bridge!!!!! And this is the first animal I have seen on the bridge!!!!' I stopped the group ... and told them — 'You are seeing the first animal on the crossing itself.' Everyone cheered. Even the lizard seemed to know it was a special occasion. He posed for the photos I took.'
Yahoo
28-05-2025
- General
- Yahoo
Letters go up on world's largest wildlife crossing over 101 Freeway
Annenberg Wildlife Crossing: Twenty-five letters that reflect years of work and decades of advocacy. On Tuesday, Caltrans announced that the letters for the world's largest wildlife crossing, which is under construction over the 101 Freeway in Agoura Hills, have officially been placed on the side of the bridge. The massive wildlife crossing will connect two natural landscapes that have been bisected by one of the nation's busiest highways, stretching over 200 feet long and 165 feet wide across the roadway. It's one of the biggest infrastructure construction projects currently underway in Southern California, and crews have been working around the clock to keep the project on track for its planned opening next year. Funded through a public-private sponsorship, the Annenberg Wildlife Crossing is named for Wallis Annenberg, philanthropist and heiress who chairs the multibillion-dollar Annenberg Foundation, a primary sponsor of the project. Wildlife crossings in SoCal aim to prevent animal deaths Other wildlife activist groups have pooled funds to assist in the realization of the project, including those inspired by the story of P-22, the world-famous mountain lion that once inhabited the hills of Griffith Park, and whose story brought attention to the plight of animals who find themselves trapped on all sides by urban sprawl. The massive undertaking is part of California's plan to identify locations where animals face barriers that keep them from moving freely, and prioritize building or converting existing infrastructure to allow them to cross more safely. The legislation was signed by California Gov. Gavin Newsom in September 2022. 'This wildlife crossing is just one example of how California is building infrastructure that connects rather than divides,' Newsom said last May. 'With projects like this, we're reconnecting and restoring habitats so future generations can continue to enjoy California's unmatched natural beauty.' A groundbreaking was held in spring 2022, but officials say more than 30 years of conservation work have gone into the preparations to connect the critical protected lands in the Santa Monica Mountains and the Sierra Madre Range. The crossing, originally estimated to cost around $90 million, is located near Liberty Canyon and is expected to open for foot and paw traffic by early 2026. Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
Yahoo
01-04-2025
- General
- Yahoo
World's largest wildlife crossing reaches critical milestone. Now what?
Monday was momentous for the Wallis Annenberg Wildlife Crossing although it still looked like a bridge to nowhere from the 101 Freeway, where more than 300,000 vehicles stream endlessly every day. Nearly three years after the project began, the critical milestone was visible only to the government officials, scientists and longtime supporters who climbed to the top: soil. And not just any soil. Over the next few days they'll be adding 6,000 cubic yards of specially manufactured soil to cover the crossing, a mix of sand, silt and clay inoculated with a bit of compost and hyperlocal mycorrhizal fungi, carefully designed and tested to mimic the biological makeup of native soils around the site. Adding soil is a big deal because it means we're nearing the end of Stage 1, when the top is seeded and then planted with native shrubs and perennials, work that should be completed this summer, said Robert Rock, chief executive of Chicago-based Rock Design Associates and the landscape architect overseeing the project. But we're still a ways from completion, now scheduled for the end of 2026, about a year later than initially planned due to delays from the heavy rains in 2022 and 2023. Stage 2, the final phase, will connect the structure to the hills at the north and south so that wildlife, like L.A.'s famous, ill-fated cougar, P-22, can use it. That stage will start with burying utility lines along a section of Agoura Road, south of the crossing, and moving water lines for recycled water used for irrigation. Read more: Saving the next P-22 starts with a million 'hyperlocal' seeds and a bare-bones nursery Late in 2025 or early 2026, Agoura Road will be closed for a few months so the roadway can be covered with a tunnel and lots of soil collected from the Malibu Lake area. The goal is to create natural slopes off the crossing — an additional 12 acres of space that will be planted with native shrubs, perennials, grasses and trees to make the crossing blend as much as possible with the surrounding hills. "Basically they're restoring the mountain to what it once was, so wildlife won't even know they're crossing the freeway," said Jeremy Wolf, mayor pro tem of Agoura Hills, who was among several government officials, scientists and longtime advocates who came to celebrate the soil's arrival on Monday. "Humans created this problem," Wolf said in an interview. "We've created islands of habitat fragmentation with our roadways and housing encroaching deeper and deeper into the wild urban interface, and now we're fixing this problem by using human ingenuity for good purposes." There has been plenty of ingenuity and innovation along the way and lots of attention to detail. For instance, even before construction began in 2022, the project built a nursery and sent horticulturists combing the hills around the site to collect about 1 million seeds from around 30 native plant species. Those seeds were planted and have been nurtured into 1-gallon pots. Mycologists (biologists who study fungi) collected beneficial mycorrhizal fungi and other microbes from the area to inoculate the soil used to grow the plants, and cover the top of the structure. They also tested what native seeds best interacted with that fungi, and chose four to sow as a cover crop before adding the plants to help "jump-start" beneficial fungi growth in the soil, which helps plants access the nutrients and water they need to thrive. Those seeds will be sown later this month, Rock said: golden yarrow (Eriophyllum confertiflorum), California poppy (Eschscholzia californica), giant wildrye (Elymus condensatus) and Santa Barbara milk vetch (Astragalus trichopodus), which supports more than 20 butterflies, including the endangered Palos Verdes blue butterfly. It took nearly a year's worth of prep to get the top ready for soil by building thick walls 12 feet tall to minimize traffic noise and visibility and adding a special drainage system to ensure water doesn't accumulate on the structure, a rubber waterproof lining and then 9 to 30 inches of a lightweight aggregate known as expanded clay shale to enhance drainage, because most native plants don't like wet feet. Meanwhile, the soil was mixed and "matured" at a site in Lopez Canyon north of Pacoima, where it has been analyzed and adjusted to make sure the pH levels and chemical compounds are balanced. Rock said their final mix had slightly elevated chlorine levels, so they had to water it deeply to help dilute and flush out that excess chemical compound. On Monday, a small army of supporters and media climbed to the top of the structure to witness the spreading of the soil. Visitors included former state Sen. and Assemblymember Fran Pavley, Agoura Hills' first mayor after the city incorporated in 1982, who fought to keep wild areas open on both sides of the 101 Freeway for some kind of wildlife crossing; wildlife biologists Miguel Ordeñana (who discovered P-22), Jeff Sikich and Seth Riley, who have long tracked and researched mountain lions and other wildlife in the Santa Monica Mountains, and Beth Pratt, the California regional executive director for the National Wildlife Federation, which helped raise the $92 million in state and private funds to build the corridor. Shortly before 8 a.m. a long, narrow conveyor device started pulling the soil from trucks at the north side of the freeway up 60 feet to the top, where it was spread around the structure with compact track loaders, essentially small earth movers that use tracks instead of wheels to minimize soil compaction. The top of the structure is 174 feet wide — wider than a football field. If the soil were spread uniformly it would be about 18 inches deep, Rock said, but the goal is to mimic the adjacent hills, so the soil is being contoured 1 to 4 feet deep, with a few pockets of small sandstone boulders. In the next month or so a few large volcanic rocks will also be craned up to the top, to match the geology of the region, which includes a small streak of volcanic rock. After the seeds have a chance to grow and energize the soil, the mature native shrubs and perennials will be planted, probably in mid-May, Rock said. Those plants, grown from locally collected seed, include black sage, white sage and purple sage, California buckwheat, long-stem buckwheat and ashy leaf buckwheat, wild grape; narrow-leaf milkweed, California bush sunflower; deerweed; showy penstemon, toyon, laurel sumac and ceanothus. Read more: 15 best native plants to grow in your yard if you also want fragrant bouquets They'll also be keeping a sharp eye open for invasives that could crowd out the newly planted native plants, aggressive plants such as black mustard, which is already sprouting lushly along the southern border of the corridor. Black mustard grows quickly and will soon be sending out seeds that could easily invade the pristine soil on the structure. But in this matter, the builders of the world's largest wildlife corridor are in the same boat as gardeners everywhere. "We'll just have to weed it until the [native] plants get established," he said. "The sad reality is there is very little else we can do." Sign up for The Wild newsletter to get weekly insider tips on the best of our beaches, trails, parks, deserts, forests and mountains. This story originally appeared in Los Angeles Times.
Los Angeles Times
01-04-2025
- General
- Los Angeles Times
World's largest wildlife crossing reaches critical milestone. Now what?
Monday was momentous for the Wallis Annenberg Wildlife Crossing although it still looked like a bridge to nowhere from the 101 Freeway, where more than 300,000 vehicles stream endlessly every day. Nearly three years after the project began, the critical milestone was visible only to the government officials, scientists and longtime supporters who climbed to the top: soil. And not just any soil. Over the next few days they'll be adding 6,000 cubic yards of specially manufactured soil to cover the crossing, a mix of sand, silt and clay inoculated with a bit of compost and hyperlocal mycorrhizal fungi, carefully designed and tested to mimic the biological makeup of native soils around the site. Adding soil is a big deal because it means we're nearing the end of Stage 1, when the top is seeded and then planted with native shrubs and perennials, work that should be completed this summer, said Robert Rock, chief executive of Chicago-based Rock Design Associates and the landscape architect overseeing the project. But we're still a ways from completion, now scheduled for the end of 2026, about a year later than initially planned due to delays from the heavy rains in 2022 and 2023. Stage 2, the final phase, will connect the structure to the hills at the north and south so that wildlife, like L.A.'s famous, ill-fated cougar, P-22, can use it. That stage will start with burying utility lines along a section of Agoura Road, south of the crossing, and moving water lines for recycled water used for irrigation. Late in 2025 or early 2026, Agoura Road will be closed for a few months so the roadway can be covered with a tunnel and lots of soil collected from the Malibu Lake area. The goal is to create natural slopes off the crossing — an additional 12 acres of space that will be planted with native shrubs, perennials, grasses and trees to make the crossing blend as much as possible with the surrounding hills. 'Basically they're restoring the mountain to what it once was, so wildlife won't even know they're crossing the freeway,' said Jeremy Wolf, mayor pro tem of Agoura Hills, who was among several government officials, scientists and longtime advocates who came to celebrate the soil's arrival on Monday. 'Humans created this problem,' Wolf said in an interview. 'We've created islands of habitat fragmentation with our roadways and housing encroaching deeper and deeper into the wild urban interface, and now we're fixing this problem by using human ingenuity for good purposes.' There has been plenty of ingenuity and innovation along the way and lots of attention to detail. For instance, even before construction began in 2022, the project built a nursery and sent horticulturists combing the hills around the site to collect about 1 million seeds from around 30 native plant species. Those seeds were planted and have been nurtured into 1-gallon pots. Mycologists (biologists who study fungi) collected beneficial mycorrhizal fungi and other microbes from the area to inoculate the soil used to grow the plants, and cover the top of the structure. They also tested what native seeds best interacted with that fungi, and chose four to sow as a cover crop before adding the plants to help 'jump-start' beneficial fungi growth in the soil, which helps plants access the nutrients and water they need to thrive. Those seeds will be sown later this month, Rock said: golden yarrow (Eriophyllum confertiflorum), California poppy (Eschscholzia californica), giant wildrye (Elymus condensatus) and Santa Barbara milk vetch (Astragalus trichopodus), which supports more than 20 butterflies, including the endangered Palos Verdes blue butterfly. It took nearly a year's worth of prep to get the top ready for soil by building thick walls 12 feet tall to minimize traffic noise and visibility and adding a special drainage system to ensure water doesn't accumulate on the structure, a rubber waterproof lining and then 9 to 30 inches of a lightweight aggregate known as expanded clay shale to enhance drainage, because most native plants don't like wet feet. Meanwhile, the soil was mixed and 'matured' at a site in Lopez Canyon north of Pacoima, where it has been analyzed and adjusted to make sure the pH levels and chemical compounds are balanced. Rock said their final mix had slightly elevated chlorine levels, so they had to water it deeply to help dilute and flush out that excess chemical compound. On Monday, a small army of supporters and media climbed to the top of the structure to witness the spreading of the soil. Visitors included former state Sen. and Assemblymember Fran Pavley, Agoura Hills' first mayor after the city incorporated in 1982, who fought to keep wild areas open on both sides of the 101 Freeway for some kind of wildlife crossing; wildlife biologists Miguel Ordeñana (who discovered P-22), Jeff Sikich and Seth Riley, who have long tracked and researched mountain lions and other wildlife in the Santa Monica Mountains, and Beth Pratt, the California regional executive director for the National Wildlife Federation, which helped raise the $92 million in state and private funds to build the corridor. Shortly before 8 a.m. a long, narrow conveyor device started pulling the soil from trucks at the north side of the freeway up 60 feet to the top, where it was spread around the structure with compact track loaders, essentially small earth movers that use tracks instead of wheels to minimize soil compaction. The top of the structure is 174 feet wide — wider than a football field. If the soil were spread uniformly it would be about 18 inches deep, Rock said, but the goal is to mimic the adjacent hills, so the soil is being contoured 1 to 4 feet deep, with a few pockets of small sandstone boulders. In the next month or so a few large volcanic rocks will also be craned up to the top, to match the geology of the region, which includes a small streak of volcanic rock. After the seeds have a chance to grow and energize the soil, the mature native shrubs and perennials will be planted, probably in mid-May, Rock said. Those plants, grown from locally collected seed, include black sage, white sage and purple sage, California buckwheat, long-stem buckwheat and ashy leaf buckwheat, wild grape; narrow-leaf milkweed, California bush sunflower; deerweed; showy penstemon, toyon, laurel sumac and ceanothus. They'll also be keeping a sharp eye open for invasives that could crowd out the newly planted native plants, aggressive plants such as black mustard, which is already sprouting lushly along the southern border of the corridor. Black mustard grows quickly and will soon be sending out seeds that could easily invade the pristine soil on the structure. But in this matter, the builders of the world's largest wildlife corridor are in the same boat as gardeners everywhere. 'We'll just have to weed it until the [native] plants get established,' he said. 'The sad reality is there is very little else we can do.'
Yahoo
31-03-2025
- General
- Yahoo
First layers of soil to be laid on 101 Freeway wildlife crossing, the world's largest
The wildlife crossing designed to help mountain lions, deer, bobcats and other creatures safely travel over the 101 Freeway between the Simi Hills and the Santa Monica Mountains will reach a major milestone on Monday, as workers lay the first layers of soil on the overpass. The Wallis Annenberg Wildlife Crossing spans the 10-lane freeway in Agoura Hills and will become the largest such crossing in the world. It is designed to help animals avoid being killed while roaming in urban habitats. Although it is too late to help Los Angeles' beloved mountain lion P-22 expand his territory, the passage will allow mountain lions and other wildlife to range farther for food and mates. Read more: P-22, L.A. celebrity mountain lion, euthanized due to severe injuries Small puma populations have been isolated by the freeway, and their offspring were showing signs of birth defects. 'I imagine a future for all the wildlife in our area where it's possible to survive and thrive and the placement of this first soil on the bridge means another step closer to reality,' Annenberg, a philanthropist, said in a statement. 'This extraordinary structure will serve not only animals," she said, "but it will reconnect an entire ecosystem and protect this global biodiversity hotspot — this moment marks another wonderful milestone toward that goal.' The Annenberg family's foundation was a major donor to the $92-million effort to make the bridge — which stands 21 feet and 8 inches above the freeway — a reality. Initially conceived more than three decades ago, construction of the 200-foot-long,165-foot-wide bridge began in 2022 and is expected to be completed in 2026. Read more: The world's largest wildlife crossing is finally standing. Here is what's coming next 'There's been a growing awareness in California as we're working to protect our nature, our biodiversity, that we can't just restore and protect habitat; We actually have to build connectivity between habitat,' Wade Crowfoot, secretary for the California Natural Resources Agency, said earlier when the project was announced. Monday morning, workers will begin placing soil — sandy loam mixed with lightweight volcanic aggregate — on the wildlife overpass. The process is expected to take several weeks and will require 6,000 cubic yards of soil, enough to cover three-quarters of an American football field in about 2.5 feet of soil. Then, coastal sage, buckwheat, wild grape, wildflowers, milkweed and other native plants will be planted on the roughly one-acre habitat. Oaks and other trees and plants will be planted on 12 acres on both sides of the wildlife crossing. Sign up for Essential California for news, features and recommendations from the L.A. Times and beyond in your inbox six days a week. This story originally appeared in Los Angeles Times.
