Since 1943, a total of 40 leatherbacks have been documented in neritic and offshore waters of the Gulf of California, Mexico: 13 as fisheries by-catch, 11 in indigenous ceremonies, 8 coastal strandings, 4 at-sea sightings, 3 observed by fishing fleets, and 1 via satellite telemetry. Leatherback hatchlings were observed on 3 occasions in the northern Gulf of California. The range of curved carapace lengths for nonhatchling leatherbacks was 113 to 160 cm curved carapace length (mean = 139 ± 12 cm). All but 1 leatherback were reported between November and May, a period of cooler water temperatures for the region.