Photo credit: Laura Bankey
Eastern Garter Snake (Thamnophis sirtalis sirtalis), photographed in Allegheny Township, Butler County, Pennsylvania.
The Common Garter Snake (Thamnophis sirtalis) is an indigenous North American snake found widely across the continent. Most garter snakes have a pattern of yellow stripes on a brown or green background and their average length is about 55 cm (22 in), with a maximum length of about 137 cm (54 in). The average body mass is 150 g (5.3 oz).