Synonyms for Gopher Snake (same or very similar meaning)
WordNet sense 1 (large dark-blue nonvenomous snake that invades burrows; found in southern North America and Mexico):
indigo snake, Drymarchon coraisWordNet sense 2 (bull snake of western North America that invades rodent burrows):
Pituophis melanoleucusFrom the ODE community, based on WordNetadd/edit