Wayne,
"Behind the times ?
Maybe a little...sounds like them Red Mountain folks are older than both of us combined."
I think I am, pretty much, up to speed on the Red Mountain phase. Their plain brown pottery is said to be pre-300 AD, thought to have come up from Mesoamerica, and be the oldest pottery in Arizona. All of that is in dispute, which is not unusual in archaeology.
As I understand it, the Red Mountain phase is not all that well researched yet, so the evidence is somewhat thin. The dating comes from a single site (pithouse) at Pueblo Patricio and only two dates were established. I believe the samples that were tested were charred logs.
Things are always in flux in archaeology. Theories that were once well accepted, like the Gladwinian model, are no longer in the mainstream. That includes the small bit of knowledge that I have gleaned over the years......no longer in the mainstream.
Take care,
Joe