Wildlife Bridge Over I-5 Gets Green Light South of Ashland
The Mariposa Wildlife Crossing would be Oregon’s first wildlife overpass and the first anywhere along Interstate 5 from Mexico to Canada.
Rendering of the planned Mariposa Wildlife Crossing. Southern Oregon Wildlife Crossing Coalition.
PROJECT SNAPSHOT
What: Mariposa Wildlife Crossing
Where: Interstate 5 near milepost 1.7, south of Ashland and just north of the Oregon-California border
Cost: $37 million
Funding: $33.2 million federal grant, matched with about $3.8 million from ODOT
Why it matters: The overpass is designed to reconnect wildlife habitat, reduce animal-vehicle crashes and help animals move safely through the Cascade-Siskiyou National Monument.
Timeline: Planning and construction are expected to be completed no later than spring 2029.
First of its kind: The project is expected to be Oregon’s first wildlife overpass and the first wildlife overpass anywhere along I-5 from Mexico to Canada.
ASHLAND, Ore. — South of Ashland, where Interstate 5 climbs through the Cascade-Siskiyou National Monument toward the Oregon-California border, the freeway cuts through one of the most biologically rich landscapes in the West.
Deer, elk, black bears, cougars, bobcats and smaller animals move through the same mountains, draws and oak-pine habitat that drivers pass at highway speed. For wildlife, I-5 is not just a road. It is a wall of pavement, noise, lights and traffic through a historic movement corridor.
A long-planned project is now moving closer to changing that.
Watch: A short project trailer explains the vision behind Oregon’s first I-5 wildlife overpass south of Ashland.
Federal funding has been released for the Mariposa Wildlife Crossing, a planned $37 million wildlife overpass that would carry animals safely over Interstate 5 near milepost 1.7, just north of the Oregon-California state line.
The project would be Oregon’s first wildlife overpass and the first wildlife overpass anywhere along Interstate 5 from Mexico to Canada.
The crossing is planned for the Mariposa Preserve area within the Cascade-Siskiyou National Monument. It would span both the northbound and southbound lanes of I-5 and include directional fencing to guide animals toward the crossing, along with habitat improvements intended to help the structure function like a natural route rather than a bridge for people.
The Oregon Department of Transportation is leading the project in collaboration with the Southern Oregon Wildlife Crossing Coalition, Southern Oregon University and a broader network of state, federal, conservation, hunting, transportation and local partners.
The Federal Highway Administration awarded the project a $33.2 million Wildlife Crossings Pilot Program grant in December 2024, but ODOT’s use of the funding was finalized only recently after months of negotiation. The federal money will be matched with about $3.8 million from ODOT, bringing the total project cost to $37 million.
A conceptual rendering shows how the Mariposa Wildlife Crossing would use a wide, planted overpass to reconnect habitat divided by Interstate 5 near the Oregon-California border. Rendering from Southern Oregon Wildlife Crossing Coalition video.
Construction is scheduled to begin in 2028, according to ODOT. Planning and construction of the bridge, fencing and associated habitat work are expected to be complete no later than spring 2029.
For the Southern Oregon Wildlife Crossing Coalition, the funding release marks a major step in a project that began as a regional vision.
The coalition grew out of a February 2021 meeting of representatives from 17 organizations and agencies. Its goal was to identify where wildlife crossings were most needed along I-5 between Ashland and the California border and to begin building a safer network for animals and motorists.
The Mariposa site rose to the top.
““We believe a wildlife crossing over Interstate 5 will improve safety for motorists while protecting wildlife,” ODOT Interim Director Lisa Sumption said. “This project would not be possible without the dedication of our partners whose expertise across many disciplines helped us develop a solid plan.””
The area is considered the highest-priority location along I-5 because of its biodiversity, sensitive wildlife populations and location within a larger habitat corridor. The Cascade-Siskiyou region links the Klamath Mountains, Siskiyou Mountains, Cascades and high desert, creating a rare crossroads where species from multiple landscapes overlap.
It is also a place where the interstate creates daily risk.
About 6,000 wildlife-vehicle collisions are reported each year in Oregon, according to state agencies. Data from six existing wildlife underpasses in Oregon, including five under Highway 97 and one under Highway 20, show an 86% decrease in wildlife-vehicle collisions near those crossings after construction.
“We believe a wildlife crossing over Interstate 5 will improve safety for motorists while protecting wildlife,” ODOT Interim Director Lisa Sumption said. “This project would not be possible without the dedication of our partners whose expertise across many disciplines helped us develop a solid plan.”
A project rendering shows the planned wildlife overpass from above, with habitat, fencing and bridge design intended to guide animals safely across I-5 instead of toward traffic. Rendering from Southern Oregon Wildlife Crossing Coalition video.
The project also carries a uniquely Southern Oregon research story.
For the past four years, Southern Oregon University students and faculty have studied wildlife movement along I-5 to help determine where a crossing would be most effective. Karen Mager, an associate professor in SOU’s Environmental Science and Policy program, has worked with students in classes and paid research internships to place and review camera trap footage near the freeway.
Those cameras have captured more than a million photos and videos. Many were triggered by wind, but SOU Computer Science and Environmental Science and Policy students used artificial intelligence to help sort the data and identify more than 20,000 unique animal images.
That data became a key part of the feasibility work that identified the Mariposa Preserve site as the priority location for the overpass.
A bobcat moves through forest habitat near Interstate 5 south of Ashland, where Southern Oregon University researchers have used camera traps to document wildlife movement around the future Mariposa Wildlife Crossing site. Photo provided by Southern Oregon University.
“This is a win not only for wildlife and driver safety, but also for the educational opportunities it will provide to Southern Oregon University students,” Mager said.
Mager said SOU has been studying wildlife along I-5 for four years to assist in planning the overpass and expects the university’s role to continue well beyond construction.
“We at SOU look forward to continuing our research to document the animals that use this wildlife overpass and share that information with the public,” Mager said.
The monitoring work is expected to continue for at least the next six to seven years, according to SOU.
That long view matters. Wildlife crossings are not just about building a bridge. They are about proving whether animals find it, trust it and use it over time.
The crossing is expected to serve a wide range of species that move through the monument and surrounding habitat. The region is home to rare mammals such as the Pacific fisher, along with deer, black bears, elk, cougars and other animals. SOU and project partners have documented many large-bodied animals near the future crossing site.
A deer and two fawns move through the Cascade-Siskiyou landscape near the planned Mariposa Wildlife Crossing, a project designed to reconnect habitat divided by Interstate 5 near the Oregon-California border. Photo provided by Southern Oregon University.
The design is also expected to benefit smaller animals, including species that may never make headlines but are part of the region’s unusually rich biodiversity.
For Oregon’s U.S. senators, the project is both a transportation safety investment and a conservation milestone.
“This project finally moving forward is a huge victory,” Sen. Jeff Merkley said. “This project will be instrumental in safeguarding all the special species that call the Cascade-Siskiyou National Monument home and protecting drivers from dangerous wildlife collisions.”
Sen. Ron Wyden said the crossing will help native animals while making the interstate safer for drivers near the state line.
“This wildlife crossing over I-5 will prove a big win for protecting animals native to southern Oregon and for making travel much safer for motorists driving the interstate just north of the California line,” Wyden said.
Amy Amrhein, co-coordinator for the Southern Oregon Wildlife Crossing Coalition, said the project shows what can happen when local, state and federal partners stay focused on the same goal.
“The Southern Oregon Wildlife Crossing Coalition, a group of 17 organizations and agencies, has been working with Oregon Department of Transportation on planning for the Mariposa Wildlife Crossing project for five years,” Amrhein said. “By working together at the local, state and federal levels, we are moving the project forward.”
A longer project feature explores the research, planning and wildlife movement behind the Mariposa Wildlife Crossing.
Once built, the Mariposa Wildlife Crossing will not erase the challenges created by I-5 through Southern Oregon’s mountains. But it will mark a new kind of infrastructure in a place where wildlife movement, public safety and landscape-scale conservation all meet.
For drivers, it may one day look like a wide, planted bridge passing over the freeway near the border.
For the animals moving through the Cascade-Siskiyou, it could become something much older and simpler: a safe way across.
Cover image: A conceptual rendering from the Southern Oregon Wildlife Crossing Coalition video shows the planned Mariposa Wildlife Crossing spanning Interstate 5 south of Ashland. The overpass is designed to carry wildlife safely over the freeway through the Cascade-Siskiyou National Monument. Rendering from Southern Oregon Wildlife Crossing Coalition video.
