The report that describes the methods, assumptions and processing of data from this assessment is: Butterfield, H.S., D. Cameron, E. Brand, M. Webb, E. Forsburg, M. Kramer, E. O’Donoghue, and L. Crane. 2013. Western San Joaquin Valley least conflict solar assessment. Unpublished report. The Nature Conservancy, San Francisco, California. 26 pages.The objective of this assessment is to characterize the land use and conservation constraints and opportunities associated with siting solar energy facilities in the Western San Joaquin Valley. This approach identifies areas with high conservation value that are important to avoid when planning energy infrastructure, as well as areas of lower environmental conflict potentially suitable for development. While the approach we take focuses on refining the conservation values in the study area, we also classify the region’s agricultural resources using simple, broadly applicable classes to begin to assess trade-offs or synergies between agricultural production, habitat conservation and energy development. In our assessment of biodiversity conservation values, we focus on core and high quality habitat for multiple listed species, including San Joaquin kit fox, and emphasize the preservation of connectivity for kit fox and other wide-ranging species. The study area for this assessment was chosen to encompass 1) all of the existing and proposed large utility-scale solar projects in the Western San Joaquin Valley, 2) all of the moderate to high suitable and high permeability kit fox habitat, including core, satellite, and recovery areas, 3) the Westlands Water District, an area that is commonly proposed as environmentally compatible for utility-scale solar development within the region, and 4) the Tulare Basin (west of Delano, CA), which is a priority conservation area for bird species and is not captured by kit fox suitability and/or permeability models. The study area is 5.7 million acres.