Nerodia sipedon, commonly known as the Northern Water Snake, is native to North America. Its geographical distribution primarily includes the eastern and central United States, extending from Maine to Georgia along the East Coast and westward to Colorado. It is also found in parts of southern Canada, particularly in the Ontario region.

The Northern Water Snake typically inhabits a variety of freshwater environments. These include ponds, lakes, marshes, rivers, and streams with slow-moving or still water. The species prefers areas with abundant vegetation such as tall grasses, reeds, and shrubs, which provide cover and hunting grounds.

Nerodia sipedon occupies the ecological niche of being an aquatic and semi-aquatic predator. It primarily feeds on fish and amphibians, contributing to the control of these populations in its ecosystem. The species is well-adapted to aquatic life, with behavior that includes basking on rocks or branches near the water and utilizing its keen sense of smell to track prey both in the water and on land.