The West isn't just a place, it's a state of mind as well. The literal West to me is everything beyond the Mississippi, the plains and the desert and the mountains.
The old West is the myth of the frontier, of finding gold and hacking out a living from the wilderness. It's male and tough and lonely, and I guess Ennis fits right into that vision.
The new West is, to me, the far west of California and the nodding donkeys of West Texas, the Castro and Silicon Valley. Jack belongs there to some degree.
DH Lawrence, who lived in New Mexico for a time, wrote about his home county, Norringhamshire in the UK, and "the country of my heart". That's what Brokeback Mountain is to Ennis and Jack, of the West but neither new nor old, a place out of time and place.