Recognized as having highly dynamic movements and specialized life histories, members of the genus Lasiurus, commonly named tree bats, have uncertain and disputed ranges. Several recent accounts of overlap, historic misidentification, and possible phylogenetic variations regarding two species of this genus; western red bat (Lasiurus blossevillii/Frantzii) and eastern red bat (Lasiurus borealis) in California, Arizona, Utah, and New Mexico have cast doubt on our understanding of their distribution, speciation, and assumed spatial allopatry. With the use of genetic sequencing utilizing tissues collected from museum and field specimens throughout California and adjoining states we can infer historic and current distribution and identify genetic variation. Appropriate species classification by region is currently being achieved utilizing mitochondrial DNA, and a more comprehensive analysis at the nuclear and genomic level will be accomplished through lower coverage whole genome sequencing. All samples include morphometrics and pelage records for identifying possible congruence in segregating the species in hand. Currently we have confirmed the existence of Lasiurus borealis in 3 counties in California. Pelage and morphometrics have shown overlap but statistically significant numbers for analysis have not been reached. The results acquired from this study will strengthen our limited understanding of this dynamic group by inferring on their basic biology, their distinctive characteristics, and altogether aid in future conservation and research.