Millions of miles of highway crisscross the United States. Highways fragment the landscape, affecting the distribution of animal populations and limiting the ability of individuals to disperse between those populations. Moreover, animal-vehicle collisions are a serious hazard to wildlife, not to mention people. Researchers at the PNW Research Station in Wenatchee, Washington, have developed methods to evaluate landscape permeability - the ability of animals to move across the landscape. Using a geographic information system, in conjunction with snow tracking, automatic cameras, and road-kill surveys, they can now identify areas where animals are most likely to cross major highways. These techniques have been adopted by the Washington State Department of Transportation in a massive reconstruction project on Interstate 90 at Snoqualmie Pass. The new stretch of highway is slated to include several wildlife crossing structures. In addition, the researchers have conducted a regional-scale evaluation of landscape permeability for grizzly bears, wolverines, grey wolves, and lynx in the Pacific Northwest. The analysis identifies highways and other landscape barriers that may fragment populations and limit dispersal opportunities. Their work provides tools that can be used to develop conservation strategies and help identify management priorities for these focal species.