Determination of trace elements by instrumental neutron activation analysis was done on turquoise from 24 mines in the southwestern United States. 30 elements were investigated; the elements Co, Cr, Eu, Sb, Sc and Ta were the most useful diagnostically. Results indicate that the turquoise artifacts from Snaketown site in south-central Arizona came from the Himalaya mine near Halloron Springs, California. The Snaketown site was occupied from the beginning of the Christian era until A.D. 1200. -- AATA