Both the pallid bat (Antrozous pallidus) and Townsend’s big-eared bat (Corynorhinus townsendii), have been proposed as covered species in the North County MSCP plan and are included in the MSP. These two species are believed to be at high to moderate risk of loss in the MSP area because of their low numbers and sensitivity to human disturbance. However, their population status, locations of roosts (diurnal, nocturnal, and maternity), primary foraging areas, water sources used, threats, and connectivity between populations in the MSP area are largely unknown. For this reason, San Diego County-wide surveys for these species were needed to document where they were found and what their current population status was. Information gleaned from these surveys will allow land managers to implement appropriate management actions to conserve their habitats. The MSP identified this work as a priority for implementation starting in 2015. In 2015, the SDNHM under contract to USGS surveyed areas with known pallid and Townsend's big-eared bat occurrences as identified in the MSP and in other high potential sites based on previous survey work by USGS and the SDNHM. A variety of methods were used (roost surveys, mist-netting, acoustic surveys, etc.) to identify and map the primary roosts and foraging areas used by pallid bat and Townsend's big-eared bat.