In 1994, the lynx was listed as a threatened species by the State of Washington; in April 2000, the U.S. Fish and Wildlife Service listed the lynx as threatened throughout its range in the contiguous U.S.
The only known resident population of lynx in the Pacific Northwest is located in an island of boreal forest habitat in the northeastern Cascade Range in Washington. Because boreal forests occur in a peninsular or insular distribution in southern latitudes, lynx habitat in the contiguous U.S. is naturally fragmented; highways and traffic that may further fragment lynx habitat could have adverse effects on critical habitat areas for lynx.
Accordingly, the influence of human activities on lynx populations in north-central Washington is of significant concern to both public and private resource managers. Some activists have argued that logging, road construction, and ski and snowmobile areas degrade or destroy lynx habitat and constrain their movements and spatial patterns.
In addition, roads and recreational trails provide human access to lynx habitat, which may disrupt hunting activities and reproduction, and increase the likelihood that lynx will be killed illegally or incidentally. However, reliable information that could be used to critically evaluate the validity of these claims is lacking. Information on the effects of paved roads on lynx is urgently needed so that managers can accurately assess the impacts of such roads on lynx movements and habitat use at the landscape scale. In particular, information is needed on the extent to which such roads may serve as barriers to lynx movements and dispersal and disrupt connectivity among sub-populations. The objectives of this study were (1) to use DNA hair-snagging techniques to conduct surveys for the presence of lynx along the Washington State Highway 20 (North Cascades Highway) corridor in north-central Washington, and (2) to attempt to document lynx crossing this highway during the snow-free period when vehicular traffic is present on the highway