Hi JasonA-EV. Since this post, Tesla has confirmed via their official site that the location is indeed Madras. The site location though is still not confirmed though. However, if I were to guess, I would say the location would be on the north side, near the airport. Currently there is a ton of new construction going on for a large truck stop, fuel center, casino, and shopping area is being constructed:

This would be the only viable area, as Madras does not have a Fred Meyers (only a Safeway with an existing fuel center), and there are no other areas that have parking lots close the size needed to accommodate a supercharger.