A Western Theme to American Religious History?

In article published over two decade ago, I argued that there three central themes to American religious history--pluralism and toleration, Puritanism and collective purpose, and the encounter of black and white--each of which came to focus in one of the regions of colonial British North America: the Middle Colonies, New England, and the South respectively. How does one think about the religious history of the American West in this framework? Is it simply an area in which the three themes noted above play themselves out? Or is there arguably a distinctive Western theme that deserves comparable attention from historians of American religion?