The Thick-billed Longspur formerly known as McCown’s Longspur, is a scarce winter visitor and migrant in Arizona. This species breeds in the shortgrass prairies of the northern Great Plains, and only a small number appear irregularly in the state, most often during late fall and winter. In Arizona, R. mccownii is primarily found in open, sparsely vegetated fields, agricultural lands, and desert grasslands, where it sometimes joins flocks of other longspurs such as Chestnut-collared Longspur (Calcarius ornatus) and Lapland Longspur (Calcarius lapponicus). Records are scattered, but notable concentrations have occurred in the Sulphur Springs Valley and San Rafael Grasslands, with smaller numbers reported from agricultural areas in Pinal and Maricopa Counties. Though never common, the Thick-billed Longspur remains a sought-after species for Arizona birders due to its localized and irregular occurrence.
