The North American racer averages 23 to 60 inches in length. Its color is variable, and the back may be brown, gray, olive, dull green or dull blue. The chin is white, throat yellow or white and the belly yellow-white to dark slate. Scales are smooth.
The North American racer may be found statewide in Illinois. This snake lives in dry prairies, open woodlands and under rocks or brush. The North American racer is primarily terrestrial but will take to water to escape when threatened. It climbs trees readily and is active in the day. It may raise its head above ground level to look around it. This snake moves very quickly, up to four miles per hour. When disturbed it vibrates its tail to make a “rattling” noise. It overwinters on rocky, wooded, south-facing hillsides or in mammal burrows. Mating season occurs May through June. The male locates a female by using his sense of smell. In late June or early July the female deposits 10 to 20 eggs under rocks or logs, in stumps or in abandoned mammal burrows. The eggs have small, grainy nodes on them. Hatching occurs by September. The racer eats small mammals, birds, reptiles, amphibians and insects.