Highway 89 stretches from north to south across California, through Sierra County from Sierraville to Truckee. The highway bisects an important portion of the Loyalton-Truckee deer herd, as well as important habitat for forest carnivores, amphibians and other wildlife on the Tahoe National Forest. By 2002, several groups were working independently to investigate different aspects of animal-vehicle collisions along the highway. These independent efforts were the: • Continuation of a 20-plus year collection of carcass information on SR 89 by Caltrans • Investigation of the effects of roadside forest thinning on roadkill by University of California-Davis Agricultural Extension Service • Investigation of radio-collared deer movements across the highway by California Department of Fish and Game • Applications to study the effects of deicing salt on deer attraction by the Sierra County Fish and Game Commission • Long-term connectivity and habitat planning by the USDA Forest Service These groups and their efforts were brought together in 2002 when they were catalyzed by the USDA Forest Service into a stewardship team to work together collaboratively to improve the high wildlife mortality and increasing habitat fragmentation on the highway. Most efforts to mitigate similar highway impacts are precipitated by a department of transportation project. In the case of SR 89, no improvement for SR 89 was planned by Caltrans. Thus, instead of responding to a tight project timeline and budget, the Stewardship Team was able to proactively develop a connectivity and mitigation plan using Caltrans’ large roadkill database, the Forest Service’s large-scale habitat maps, and the other cooperators’ information. In 2004, Caltrans independently funded a $720,000 wildlife-mitigation project on SR 89, thus allowing the Stewardship Team to use its connectivity plan as the basis for decisions on prioritizing wildlife crossing structures. The Stewardship Team is using the connectivity plan to propose further mitigation to Caltrans after the initial structure is constructed. The Stewardship Team has also secured grant funding to involve the local high school in a long-term investigation of how habitat connectivity and highway impacts are related. This presentation traces the efforts of the Stewardship Team member agencies and how their diverse contributions, once coordinated, supported a grass-roots effort to mitigate highway impacts on SR 89.