What's more, we tend to think of the "West" as "won" but these states are mostly still growing as part of the American Westward expansion. A lot of Western State land only became easily accessible with the completion of the interstates in the 1960s 1970s and even 1980s. Therefore, the material abundance necessary for truly large scale populations to live in comfort has only come to these places in the last 40 years. This has caused a consistent population boom in some places which is not yet tapering and will lead to increased stress on these resources.