By 1941, Punta Penasco, 187 inhabitants dedicated to fishing or working on the railroad Sonora-Baja California, Mexicali, which stretch Rocky Point, was opened in 1940. He later pleaded Municipal Police, which began settlements in what is today the city.
Later, on July 9, 1952 was erected the town of Puerto Peñasco, Caborca and comprising separating the towns of Sonoita, Bahia La Choya, March 21 and Cuauhtemoc. For 1989, the municipal area is a reduction in its territory with the creation of the municipality in the state number 70, General Plutarco Elias Calles.
Once we defined the area and no change in June 1993 he received the custody of the Biosphere Reserve of the Upper Gulf of California and then integrates the Biosphere National Park Pinacate and Gran Desierto de Altar.