Oddly enough, this rumor/possible facility came to my attention from someone in the construction industry, as the property is currently owned by Sukut Equipment.
For anyone familiar with the Southern California area, this should make sense. Going West bound on the 91 freeway out of Corona, there's the 71 North. If you get on the 71 going Northbound, there's a quarry on the left hand side about one mile after you get on it. Supposedly Monster Energy, or someone with Monster backing it, has struck a deal to fill in this quarry and build an auditorium style cut out in the hillside for an off-road truck track and there would be a motocross track in the facility as well.
This suggested location is only a couple miles from Pro Circuit and Monster Energy's main shipping center...with Monster's HQ being just down the freeway to the East a few more miles.
Check out the google Earth image below. Be interesting if this all pans out...according to what I heard, it sounds like it's a go.
