The Bull Snake (Pituophis catenifer sayi) was a great find... had one for a pet as a kid. Back then they were considered their own species, but have since been reclassified as a sub-species of Gopher Snake.
This morning's ride was on the city streets, but rides in the not so distant past have yielded a rattlesnake (missed hitting it by inches), and a Peregrine Falcon, which I got to see go down after something, out of sight into a field. Saturday's group ride passed a large, dead, Western Diamondback rattler. My favorite of the animals I'm apt to see on my commutes is the Roadrunner.