It has previously been thought that only one species in the genus Lepidurus occurs in California’s Great Central Valley, USA - the federally listed as endangered vernal pool tadpole shrimp (Lepidurus packardi). However, the alkali tadpole shrimp (L. lemmoni) was observed in the southern portion of the Central Valley in 2019 within several alkaline playa pools. This species’ presence in the Central Valley likely represents a remnant historic native population concentrated between 0 to 25 km south of the southern edge of the historic Tulare Lake. Alternatively, the occurrence may be a natural or anthropogenic range extension or perhaps a new species. The discovery of a species (or possibly new or cryptic species) very uncommon to the Central Valley provides additional management implications that Tulare Basin pools provide habitat for rare species at risk of development and should be protected. Furthermore, alkali pools within this region should receive more intensive and widespread survey attention, especially from a large branchiopod perspective.