The snake tribe Lampropeltini (the king, milk, pine, rat, short-tailed, long-nosed, scarlet, and glossy snakes) comprises a well-known group of common colubrids distributed throughout North America and northern South America. However, a robust phylogeny has thus far proven elusive. We infer a new phylogeny for the group including all known extant species based on multiple nuclear and mitochondrial genes, and present a revised taxonomy. We test the hypothesis of a Pleistocene 'species pump' being responsible for diversity in the group. We find that diversification of the lampropeltinines took place in the Neogene, rejecting the common model of a Pleistocene radiation.