We frequently find this plant at native village and camp sites.

Native Californians believed that if the partakers had prepared themselves in advance by observing all of the restrictions on diet and sex, and if they approached the experience with a calm mind, then Datura put them in contact with the supernatural.

This healthy plant was observed in Horse Valley near the bedrock mortars on Empire Mine Road in Antioch.

Datura Wrightii is the desert species here, which is found transplanted all over the  Central Valley at Native American archaeological sites from the Sierra foothills to the Inner Coast Range, and from Redding to Bakersfield. The five points on the beautiful white flower are diagnostic for this species of Datura which was praised and used ceremonially in various rites because of its BIG TIME HEAVY MEDICINE. The Valley Yokuts particularly used this in their TOLOACHE CULT ceremonies which overlapped with the KUKSU CULT in the Sacramento Valley to the north. Datura connected them to the Spirit World

Doc Hale

I have found Datura at a huge percentage of sites throughout the southwest. In the Santa Barbara Chumash territory it grows right up to the beach, and I have seen it growing out of small cracks in vertical rock faces of both pictograph and petroglyph sites. Seeds must have been put there by shamans, as I can’t see any other way of them getting into such unique spots. The largest patch I have ever seen was on the hillside directly behind the Painted Rock in the Carizzo Plain. The conditions for that particular year must have been just right, as the patch was very thick and dense, covering the size of a city block.

Barefoot Dave

reference: The Datura Cult Among the Chumash, by Richard Applegate