In this dissertation I address the evolutionary history, ecogeographic variation, and phylogeography (single species and comparative) of collared pikas (Ochotona collaris ). Pikas are small (ca. 150 g) lagomorphs (order Lagomorpha: rabbits, hares, and pikas) found in alpine habitats throughout much of the Holarctic. Only two of the 30 extant pika species occur in the New World. The northern of the two species, O. collaris is separated 800 km north of the American pika (O. princeps ). In the first chapter, I employ recently developed molecular analytical techniques to examine when the two North American species diverged. This chapter sets the evolutionary context for the subsequent diversification within O. collaris. In the second chapter, [...]