"T.l. arenicola" has been proposed by the American Ornithologists Union as separate species, and treated as a separate species by other authors. and a name of Vizcaino thrasher if it becomes official. T.l. arenicola still is treated as a subspecies of "lecontei" by some authors, however. A proposed race "T.c. macmillanorum" only exhibits minor differences in plumage from "T.l. lecontei" (such as a darker crown and lighter flanks), but is not justified by biochemical or morphological grounds. One study suggested that the phylogeographic structure of the LeConte's is consistent with both its geographic distribution and genetics, with the Vizcaíno Desert in Baja California acting as a barrier initiating allopatric speciation.