Where was the Proto-Uto-Aztecan homeland likely located?

The Proto-Uto-Aztecan homeland is believed to have been located in what are now Arizona and northern Mexico, with the possibility that it also extended into southern California.1

Linguistic evidence suggests that speakers of Proto-Uto-Aztecan were not agriculturalists, as no terms for cultivated plants or agricultural techniques can be reconstructed for the protolanguage. This finding contradicts hypotheses suggesting that these speakers practiced agriculture and migrated from Mesoamerica to the north. Instead, the Southern Uto-Aztecan branch later spread into the northern Middle American zone, with the Aztecan (Nahuan) group eventually entering Mesoamerica.1