The San Dieguito River Valley
Home of Sineywheche, Pa’mu,and ‘Ellykwanan
by Richard Carrico, Archeologist

From the mouth of the San Dieguito Lagoon on the ocean front to the arid slopes of Volcan Mountain on the edge of the desert, the San Dieguito River winds through almost 10,000 years of prehistory. No other river in southern California cuts across so many cultures and archeological sites. The characteristics of the river, that draw us to it today, have been a magnet to people for thousands of years. Whether you hike the trail system, visit one of the landmarks along the river, or enjoy the landscape from your armchair, the long and rich prehistory is sure to engage you.

The First People.

The first inhabitants of the region are aptly named the San Dieguito, after the place along the river near Rancho Santa Fe where their ancient stone tools were first excavated in 1928. The Harris archeological site on the south banks, now within the Crosby Estate development, is the oldest archeological site in San Diego County and the source of scientific study for more than 75 years.

The people of the San Dieguito Complex fashioned elaborate stone tools from the metavolcanic rock that extrudes from the ancient river channel between Rancho Santa Fe and Lake Hodges. The spear points, knife blades, and scrapers manufactured by these craftsmen were used to dress the abundant game that foraged throughout the San Dieguito River Valley. The people drank from the clear springs in the nearby hills and made use of ponds formed by natural volcanic dikes that now echo with the voices of golfers and hikers. The prehistoric animals and waterfowl that came to the ponds found their way into the San Dieguito larders.

Archeologists have determined that the San Dieguito lived in the area from at least 9,200 years ago until approximately 8,000 years ago. Whether these ancient people blended into a later dramatically different people or gradually evolved in response to environmental change is one of the mysteries of archaeology.

The Millingstone People.

A visitor to the lower San Dieguito River around 8,000 years ago would have witnessed the dawning of a new era in the region. The people who swam in the river and quarried the fine grained stone for tools were blessed by nature’s abundance. They bore little technological and cultural similarity to the people of the San Dieguito era.

The large, finely made stone tools gave way to milling tools for processing native grasses and seeds. Shellfish from the lagoons and beach sands fed more people than large game. Canoes or rafts took fishermen off shore at Del Mar where the sea teemed with fish and marine mammals. From the mouth of the Del Mar lagoon to sites inland at Poway, these people called the San Dieguito River their home.

Known in the archeological literature as the La Jolla people, after the first sites discovered near La Jolla Cove, these people made shell ornaments, buried their dead with grave goods, wove elaborate mats, and for more than 5,000 years thrived on the coastal plain and adjacent inland valleys. Archeological sites at Fairbanks Ranch, the Del Mar Slough, Crosby Estate, and other places along the San Dieguito River attest to the intensity of human occupation in this era from 8,000 to 3,000 years ago.