I always enjoy watching dates been rolled back to the times that my own ideas fully support. I am comfortable that this region was influenced by Atlantean copper traders in the late second millennia BC and possibly sooner.
There is an old saying in fraud investigation to follow the money. In the Bronze Age, money was copper. Every good copper district in the Americas and elsewhere were potential sources for the raw material. The seamen came in their vessels and established trading factories and motivated the locals to produce the copper.
An echo of that mining impulse led also to the collection of gold in the Andes and South America. What woke me up was the remarkable fact that the Incas held gold reserves equivalent to several thousands of years of mining effort using indigenous methods. However you wish to recast those numbers, there was some explaining to do. The big one was why? Ignited by trader’s buying habits makes imminent sense and holding it then as a store of wealth and accepting it as taxes also makes sense. And just who were the Andean counter trades with? That those traders had disappeared while the currency system just went on and on actually works very well in the case of the Inca.
I got this out of a group called alt.archeology.moderated run by a chap who collects press clippings on archeology world wide and has been doing it for a good decade. The link to the source article got wrecked.
Archaeologists have unearthed the remains of an ancient farming community at a site called Las Capas in Arizona. The settlement dates to 1200 BC-800 BC, the early agricultural period in the Southwest. The settlers at Las Capas created a system of canals now proven to be the earliest extensive irrigation system in the Southwest. These canals pre-date the Hohokam canals by 1000 years. This find has completely revised the history of organized irrigation in the Southwest. The canals were built in grids with earthen gates to regulate flow. The canals held running water 9 months out of the year. The area covers 100 acres and supported 150 people. The Las Capas people grew maize as their primary crop using popped corn to make tortillas. They gathered cactus fruit, mesquite pods and amaranth. Skeletal remains of the Las Capas people show they lived a healthy life. Circular pit houses have also been uncovered with charcoal remains used for cooking in shallow pits. They had domesticated dogs and other domesticated animals.
There are 7 other settlements nearby with evidence of canals there as well. A massive flood in 800 BC destroyed their society as the Las Capas people made attempts to rebuild the waterways and then abandoned their village.