The first recorded use of tracer techniques in North America occurred slightly more than two and a half centuries ago, and was the work of Eusebia Francisco Kino. Using the blue shells of the common abalone as a trace element, Kino demonstrated, by rigorous reasoning and diligent field investigation, that there was extensive trade and travel between the Pacific coast, where the abalone occurred and the desert land of Papagueria, where the abalone shell was present as a trade item, serving not only as a kitchen utensil, but also as the raw material for many decorative artifacts.