The California spiny lobster (Panulirus interruptus) ranges from Monterey Bay, California to Manzanillo, Mexico. There is also a small, isolated population of this species at the northwestern end of the Gulf of California. The majority of the population is found between Point Conception, California (Santa Barbara County) and Magdalena Bay, Baja California, Mexico. Adult lobsters usually inhabit rocky areas from the intertidal zone to depths of 240 ft or more.

Based on a mitochondrial DNA analysis of the California spiny lobster along the Pacific coast of Baja California, García-Rodriguez and Perez-Enriquez (2006) did not find any genetic differences in the population, suggesting that there is a single population in the north Eastern Pacific. The notion that there is a single population has been also suggested based on the larval distribution (Johnson 1960; Pringle, 1986) and adult abundances (Vega 2006) with a center of the population in the central part of the peninsula.