The Spanish arrived in the area after crossing the Sonora Desert's "Camino del Diablo" or Devils Road. This led to the evangelization of the area and also the population reduction of the native peoples. Today, indigenous Cocopah people still inhabit a small government-protected corner of the delta near the junction of the Hardy and Colorado rivers. These people mostly work on agricultural ejidos or fish the rivers, although many have migrated to Mexicali.
The early European presence in this area was limited to the Jesuits, who left in the 1780s. After this, the Spanish and later the Mexicans had little to do with the northeastern corner of the Baja California peninsula, perceiving it as an untamable, flood-prone desert delta.
19th century
In the mid-19th century, a geologist working for the Southern Pacific Railroad came to the delta area, discovering what the native Yumans had known for centuries: that the thick river sediment deposits made the area prime farming land. These sediments extended far to the west of the river itself, accumulating in a shallow basin below the Sierra de Cucapá. However, from this time period until the 1880s, the area was almost completely unpopulated, mostly due to its climate. In 1888, the federal government granted a large part of northern Baja state, including Mexicali, to Guillermo Andrade, with the purpose of colonizing the area on the recently-created border with the United States. However, around 1900, the only area with any real population, aside from the Cocopah, were concentrated in Los Algodones, to the east of Mexicali.
20th century
In 1900, the U.S.-based California Development Company received permission from the Díaz government to cut a canal through the delta's Arroyo Alamo, to link the dry basin with the Colorado River. To attract farmers to the area, the developers named it "The Imperial Valley". In 1903, the first 500 farmers arrived; by late 1904, 405 km² (100,000
