Vandenberg Space Force Base (VSFB), located in northern Santa Barbara County, California, is one of the very few military installations in the U.S. which is home to western monarch butterfly (Danaus plexippus) overwintering sites. The monarch butterfly is currently a candidate species for listing under the Endangered Species Act, and it is therefore crucial to understand which overwintering sites are used by monarchs, and what management is needed at those sites. In 2022 and 2023, we increased our overwintering monarch monitoring efforts, conducted standardized habitat assessments, and began searching for new overwintering sites. We also partnered with multiple organizations to bring monarch and monarch habitat focused research projects to VSFB. In 2022 we monitored 28 overwintering sites, and in 2023 we monitored 36 sites (including 3 newly discovered sites). We also conducted habitat assessments at 27 sites. These efforts have allowed us to identify the most important overwintering sites on VSFB and draft mission-compliant habitat management actions for those sites (including habitat restoration/enhancement).