Fish & Wildlife research & reports

This page features wildlife research relevant to transportation and supported by the Washington State Department of Transportation (WSDOT). Find reports by topic in the list below.

Statewide habitat connectivity analysis

The Washington Wildlife Connectivity Working Group (WWCWG) was established in 2007 to produce tools and analyses that identify and prioritize opportunities to provide habitat connectivity around the state. WSDOT and the Washington Department of Fish and Wildlife co-led the group.

In 2010, the WWCWG published a statewide analysis of habitat connectivity that identified areas around the state important for wildlife movements. WSDOT uses this information to establish priorities for investing in more wildlife-friendly highways. These investments include installation of roadside fencing, crossing structures, or a combination of the two.

Wildlife habitat connectivity considerations in fish barrier correction projects

The corrections to barriers to fish migration present an opportunity to provide connectivity for other species as well. Use the wildlife passage criteria and guidance in this document when designing fish passage structures. 

Ranking the suitability of existing bridges and culverts for providing wildlife passage

This WSDOT-funded research project developed a new method to rank the suitability of existing transportation structures for wildlife movement. Julia Kintsch and Dr. Patricia Cramer’s research included the development of the Passage Enhancement Toolbox, a compilation of potential solutions for retrofitting structures to make them wildlife-friendly.

This project used motion-triggered cameras to monitor wildlife use of bridges and culverts around the state. The short video below shows a selection of images captured by these cameras. 

View the original research, enhancement toolbox, or video footage:


Black bear family using a WSDOT culvert.Bucks using a WSDOT culvert.Bobcat using a WSDOT culvert.

Landscape permeability for large carnivores 

This report assesses wildlife movement using GIS weighted-distance and least-cost corridor analysis.

Download maps and figures:

Wildlife crossings and collisions analysis