In the second half of the Twentieth Century, a historic redistribution of the American population brought into being the New American West. The "opulent, energetic, mobile, and individualist" cities of Southern California seemed to perfectly project America's national future,1 but there were troubling signs, too. Images of urban sprawl and clogged freeways and highly publicized incidents of racial violence and ethnic tension signaled a gradual "withering of California's Pacific Idyll."2 An increasing number of the state's residents began to spill into the Intermountain West, and at the same time people moving from other parts of the country began stopping short of the Pacific. Today, four rapidly growing urban constellations located at the margins of the Great Basin Desert constitute the most recent, and perhaps the last, of the series of urban frontiers that have shaped America's cultural and political outlook.3