The One Lake project is a large-scale, transit-oriented, mixed use residential and commercial development and public infrastructure project which at build-out will affect 378+ acres of California tiger salamanders (CTS) breeding, movement, and upland habitat. Habitat loss, fragmentation, and degradation are threats to CTS populations. To further sustain the regional CTS population, 668+ acres of on-site mitigation were set aside in perpetuity including 14 created CTS breeding pools, reestablished and rehabilitated seasonal wetlands, and constructed mounds. Despite drought conditions, capture and relocation to on-site mitigation areas resulted in handling/monitoring of 8,310 CTS (7,939 larvae and 371 adults, juveniles, and metamorphs) from November 2018 through December 2022. Under our mitigation criteria the 14 CTS breeding pools were created, and CTS were documented successfully breeding in four of these pools and a fifth adjacent pool on an established conservation bank in the winter of 2021-2022. No CTS have been relocated to three of these pools since 2019. Relocation of CTS adults and larvae combined with enhanced mitigation areas have resulted in the continued success of an isolated CTS population in Solano County.