Garter snakes can be found in nearly every environment in North America, with typical boundaries ranging from the sub-Arctic plains of Canada all the way to Central America. These snakes are most common around the moist, grassy environments of the United States' east coast.
Garter snakes live almost exclusively near sources of water. As such, their numbers are less common around the arid west coast of the United States. They are very adaptable creatures and are suited to live in a variety of areas, such as forests, grassland, swamps, fields and wetlands. They have been found as far north as coastal Quebec and as far south as the Gulf of Mexico.