Shasta-Trinity Project
I-5 is a major interstate that runs North-to-South and poses a significant barrier to wildlife movement and risk to public safety. According to a statewide deer-vehicle crash hotspot analysis, three of the ten worst hotspots within the State Highway System are located on Interstate 5.
The stretch of I-5 spanning from Shasta Lake to Weed, CA bisects important habitat for bear, deer, pacific fisher, marten, and elk.
The California Department of Fish and Wildlife has also identified much of this stretch of highway as a priority barrier to wildlife movement.
This stretch of I-5 also bisects modeled connectivity linkages for both Pacific Fisher and Pacific Marten.
Did you know? The Shasta salamander (Hydromantes shastae) is only found in the Shasta Lake region in northern California and nowhere else in the world. It has the smallest known range of any Pacific Northwest amphibian.
In January 2020, PEW Charitable Trusts funded a symposium with Caltrans, CA Dep't of Fish and Wildlife, and the Pit River Tribe, and summary report, completed by SC Wildlands, that identified future transportation projects that have the highest biological priority and greatest safety benefit to the public.
This report identified various areas on this section of highway that would benefit from improved permeability and gaps in information.
In addition, the SHOPP Projectbook indicates several relevant projects on identified problematic stretches of highways.
This stretch of highway only has a few existing culverts and bridges that are widely dispersed and need verification to determine wildlife use, especially by pacific fishers, post-fire.
Caltrans project will address 3 bridges and scope of project is under development. (SHOPP ID # 22140)
Especially on the southern half of this stretch, underpasses are often blocked and need better assessment.
Observed bear and other wildlife movement towards Sacramento River and back. The concrete barrier on this stretch of highway impedes movement. Maintenance data and camera data are needed to pinpoint where wildlife are attempting to cross in this region.
Recorded bear and deer roadkill on this stretch.
Caltrans maintenance reports ~1 kill/month since the median barrier was constructed, approximately 10 years ago. This is a common crossing location for sow with cubs.
On this stretch, Caltrans is in the planning stages of rehabilitating one bridge, replacing and rehabilitating culverts, and addressing 128 drainage systems in 2025/26.
Given the timing, nature of the project, and location, this could be a great opportunity for addressing terrestrial connectivity.
This stretch of I-5 has private lands on both sides but public lands further out from the highway. Some land in this region is in recent conservation easement with Pacific Forest Trust (PFT). PFT is interested in creating wildlife infrastructure here and other locations.
