Around the year 1800 the Yaqui Indians set up camp along the northernmost coast of the Sea of Cortes and waited for Father Kino to show up and convert them to Christianity. Upon arrival, the village of The Gulf of Santa Clara was established. Because of the many animal species, marine mammals and beach birds, the strip of land where the Sea of Cort�s ends, or some would say begins, is one of the planet�s richest ecosystems. Today the sea and river converge in the municipality of San Luis Rio Colorado. The divergent waters, one fresh and one salt, seem to merge in close communication forming a majestic sight. This can only be seen and enjoyed in the Gulf of Santa Clara. The Mexican government recognized the richness of this ecosystem and declared this area as the Upper Sea of Cort�s and Colorado River Delta Biosphere Reserve in June 1996. The Gulf of Santa Clara, or also known as "El Golfo", is an area that has gradually grown in interest to locals and visitors alike given its features. Located only 90 miles south of Yuma, Arizona, while it may not be everyone�s idea of an ultimate vacation destination, if you like sand and sea, you will love El Golfo. El Golfo is one of the best-kept secrets in the Western Hemisphere.
As recently as the mid 1920's a small and little known port of activity flourished on the Colorado delta. Known as Santa Isabel, it was located some 8 miles west-northwest of present day El Golfo. It was a very strategic stopping off point for the many steam ships, which supplied the army and mining interests on the upper Colorado. Today Santa Isabel is nothing but a memory as it was abandoned with the damming of the river and today all traces of its existence have vanished. In the early thirties, the State of Sonora provided funds for a road across the desert and with this new road came the village of el Golfo de Santa Clara.
Archeological findings have been made in this reserve that date back to 9350 B.C. This helped to confirm that the first settlers were San Dieguito ancestors from the Odham culture.