This chapter provides a brief overview of the rivers that lie within the Arctic region of North America, a vast area that encompasses northern regions of Alaska and Canada. It focuses on four rivers (three from Alaska and one from Canada) within the Arctic region. These rivers represent a spectrum from pristine unimpaired waters (the Noatak and Kuparuk rivers) to those potentially influenced by oil development (the Sagavanirktok River) and finally, to a large river system flowing into Hudson Bay, which has been influenced by hydroelectric dams and other basin developments, including mining and forestry. Permafrost has a major influence on the landscape of the Arctic region and rivers flowing within it, resulting in dominance by thermokarst features. The freshwater ecoregions of the North American Arctic are divided into two large complexes. The Noatak, Kuparuk, Sagavanirktok, Thelon/Kazan, and Seal systems are included in the Arctic complex; and the Moose River is in the Hudson Bay complex Streams and rivers in Arctic Alaska and Canada display unique physicochemical characteristics, due in many respects to the influence of snow and ice. Hydroelectric power generation in northern Alaska has not had a significant influence on river basins, but in Canada, particularly on a number of the rivers flowing into Hudson Bay, dams have exerted a major influence on river hydrology.