Watershed Map of North America

Every bioregion starts with it’s watersheds. This map depicts in full color and detail the different watershed basins and regions located within North America at a scale of 1:10,000,000.

A watershed is an area that stretches from where a raindrop falls, to where it ends. Any watershed might be a part of a larger watershed, and they form the basis for larger ecoregions and bioregions. Within these large units, subsequently smaller units encompass the drainage areas of smaller rivers and streams.

This map shows the major North American drainage basins, or watersheds, which drain into the Atlantic Ocean, Hudson Bay, Arctic Ocean, Pacific Ocean, Gulf of Mexico and Caribean Sea. Each watershed is shown in it’s own color, with subdivisions shown in tonal variations. Areas of internal drainage, which lack outlets to the sea, are shown in gray.

Watersheds are classified differently in Canada, Mexico and the United States; the data set includes a continental classification (the North American Watershed, or NAW level), as well as the classification unique to each country. This data set was compiled from each country’s watershed file and adjustments were made to the data to resolve misalignments and mismatches across international borders.

This map was created as part of a joint effort by the Atlas of Canada, Instituto Nacional de Estadistica, Geografia e Informatica and the Commission for Environmental Cooperation (CEC), and is a reprint edition made with permission of the original creators and with full attribution. Contains information licensed under the Open Government Licence – Canada.