San Clemente Island (SCI) is a U.S. Navy-owned island composed primarily of maritime desert scrub and invasive grassland vegetation communities. There are two species of mice on SCI; the endemic deer mouse (Peromyscus maniculatus clementis) and the introduced house mouse (Mus musculus). Both species are a food source for endemic predators including the island fox (Urocyon littoralis clementae), loggerhead shrike (Lanius ludovicianus mearnsi) and raptors. We have used capture-recapture data to calculate density for both mouse species since 2015. In late-July 2024, a wildfire burned approximately 25% of SCI’s land area including one of our mouse sampling trap grids. Because no grid had previously burned, this fire provided an opportunity to examine the effects of wildfire on SCI’s mouse population. We conducted capture-recapture sampling one month after the fire over 245 trap nights. Density of deer mice remained stable and house mice increased one month after the fire compared to sampling conducted 3-weeks prior to the fire. Further capture-recapture sampling will be conducted to determine long-term effects of fire including the impact of increased fuel load densities and how these factors influence mouse densities. These results help us better understand fire vulnerability for these key species.