The risk of catastrophic wildfire is now the most pressing concern of western public land managers, and there is near universal agreement among researchers that the return of fire as an ecological process is a critical step in restoring ecosystem integrity. At the same time, public land managers are mandated to manage habitat such that viable populations of native vertebrates are maintained. Of particular concern are species such as the Pacific fisher (Martes pennanti) which rely on many of the same structural characteristics that make a forest prone to a catastrophic fire. It is typically assumed that fuel reduction will have a negative impact on species such as the fisher, but that any direct negative consequences are outweighed by the indirect benefits associated with reducing the risk of large, catastrophic fires that result in habitat destruction. However this assumption is often challenged in court and implementation of fuel management projects is often blocked by litigation. While several ongoing research projects are addressing the long-term, population-level effects of fuel management on fishers, there is currently no information available on the short-term response. The only available data come from modeling studies that evaluate the impact on the species based on perceived changes in habitat quality. At the request of numerous land managers across the southern Sierra Nevada, we propose to fill this gap by using GPS telemetry to monitor the immediate response of fishers to fuel management projects across their range in California and Oregon. Because large-scale experimentation is nearly impossible at the scale necessary for even mid-sized carnivores, we propose to capitalize on upcoming thinning and prescribed burning projects on public and private land throughout the Sierra and Klamath regions. We propose to deploy 5-7 GPS collars on resident fishers at up to seven fuel management projects per year in conjunction with intensive pre and post treatment vegetation surveys. Previously, fine-scale data on fisher movement patterns have been nearly impossible to obtain due to fishers rarity, small body size, large spatial requirements, secretive nature, and the ruggedness of the terrain they inhabit. However as part of the Kings River Fisher Project (KRFP), scientists from the USFS Pacific Southwest Research Station have worked with telemetry engineers to develop a fisher-sized GPS collar weighing less than 70 grams and capable of recording >1500 GPS locations. The collars are designed not to impede a fishers natural agility and the data can be remotely downloaded from the base of a rest tree or from the air. By incorporating numerous agencies and fuel management techniques across the region, and by using previously unavailable technology, the proposed project will capitalize on existing fuel reduction projects, build on past research, and will facilitate a realistic landscape-level assessment of the impact of a range of fuel treatment options on fishers. It will open a new window into the impacts of fuel and vegetation management on sensitive, elusive wildlife, help managers to design projects that minimize the negative impacts to fishers, and facilitate the placement of treatments on the landscape in such a way that habitat integrity is maintained. This project will generate critical data at two spatial scales; facilitating local research efforts that will provide managers the information they need to plan and execute fuel management programs, and coordinating these local efforts into a more comprehensive regional analysis such that more general guidance on how to minimize the negative effects of treatments can be provided.