North Boulder County Wildlife Crossings Project- US 36 between Boulder and Lyons

Boulder County Open Space, along with our partner departments of Transportation and Public Works, is pursuing implementation of wildlife crossing structures on US Highway 36 between Boulder and Lyons, specifically between Left Hand Canyon and US Highway 66. There are several reasons for our formalized pursuit of wildlife crossings. Boulder County has been concerned about the safety of the public and the wildlife due to the high level of annual wildlife-vehicle collisions in this stretch. As the primary landowner of the adjacent lands along this stretch, Boulder County is ready to take the steps necessary to address this issue, to protect wildlife and our residents and visitors.

As a County, we feel well-positioned to accomplish this project. Our Open Space wildlife biologists have been carefully tracking deer and elk movement patterns for many years. This has been achieved through a close working relationship with Colorado Parks and Wildlife district wildlife managers and area biologists. We have several years of elk collar data which have provided a clear understanding of annual elk movement patterns. These data also provide valuable information on the large-scale patterns of habitat use by elk from the plains to the continental divide.

Additionally, we have vetted the concept of wildlife crossings with our public through our 2020 Red Hill Elk Management Plan (BOCO, 2020) process, which emphasizes our intentions to pursue safe facilitation of wildlife across US Highway 36. The issue of this problematic stretch of US Highway 36 has also been highlighted by our 2020 Transportation Master Plan Update, which conducted a comprehensive analysis of wildlife-vehicle collisions in all of Boulder County. The results show that 40% of all wildlife collisions in the entirety of Boulder County occur in this stretch. So, while we’ve been acutely aware and concerned about this deadly stretch in our County, we were awaiting the results of the Eastern Slope and Plains Wildlife Prioritization Study (Jacobs, 2022) for statewide comparative context. This stretch of US Highway 36 is ranked in the top 5% of segments needing mitigative actions, and in fact, based on the study’s modeling inputs, this stretch received the highest score in the Colorado Department of Transportation’s (CDOT) Region 4. The ESPWPS results were the final catalyst for Boulder County to move forward with pursuing an analysis of the corridor for crossing location considerations, prioritizations, strategies, and cost estimates.

Throughout this planning process, we’ve held several public meetings, developed a webpage, and have showcased our project via webinar participation. We will continue these outreach-focused efforts for the duration of the project by reaching out to landowners, public citizens, and local groups over the next weeks, months and years.

Susan Spaulding is a wildlife biologist whose career started with field studies for federally threatened and endangered species including desert tortoise, northern spotted owl, and marbled murrelets. Her years of transient and delightful field work lead to a permanent biologist position with the U.S. Forest Service at the Lake Tahoe Basin Management Unit. After several years, Susan moved back to her ‘native’ Colorado and started working for Boulder County Parks and Open Space as their Wildlife Program Supervisor. Currently she is developing a program that is focused on multi-jurisdictional collaborative projects, such as beaver habitat enhancements and beaver reintroductions, Preble’s meadow jumping mouse Federal Recovery Plan implementation, and wildlife crossings on US36 and Hwy 128. She earned her undergraduate degree in Environmental Population Organismic Biology at CU, and her graduate certificate in Geographic Information Systems at the University of Denver.