Scomberomorus sierra is endemic to the Eastern Pacific, and is found from La Jolla and Santa Monica in southern California and the Gulf of California to Antofagasta, Chile including the Galápagos, Cocos and Malpelo Islands (IUCN 2008); it is mainly harvested in Mexican waters (~75% of total catches; http://www.fishbase.org/summary/136).

Some studies on stock structure have been conducted in the Mexican coast. Ramírez-Pérez et al (Ramírez-Pérez 2010)  found some phenotypic structure of the populations based on otolith morphology and size-at-age differences, but such results were not supported by genetic analysis of mtDNA which suggested no population structure along the Mexican coast (Ramírez-Pérez 2010); suggesting that management should be conducted at a large scale covering the whole distribution of the species.

However, López et al. (López et al. 2010) suggests the existence of at least two stocks in Mexican waters: a northern population localized at the mouth of the Gulf of Baja California (Sinaloa), a second population in the Gulf of Tehuantepec (Oaxaca). This conclusion is based on a genetic study using mtDNA. The study further suggests that other populations might be present as no samples from the northernmost area of distribution (off Baja California) were analyzed.

The stock structure is therefore unclear and no formal assessment is known to be conducted so a management unit within Mexican waters is considered.