Each year American Rivers analyzes the condition of the nation's rivers to determine which are the most “endangered.” Threats to these rivers include dams and channelizations that are harmful to fish or wildlife populations; depletion due to the rivers' use as a water supply for human populations; and coal mining operations that fill streams with coal and dirt. For more information, refer to the American Rivers web site: http://www.amrivers.org/mer00rivers.html.

Rank River State(s) Threat(s)
-------------------------------
1. Missouri River Mont., N.D., S.D., Neb., Kans., Iowa, Mo. Six federal dams
2. Canning River Alaska Oil, gas drilling
3. Eel River Calif. Two dams
4. Hudson River N.Y. PCB pollution
5. Powder River Wyo., Mont. Water pollution from planned natural gas extraction
6. Mississippi River Minn., Wis., Iowa, Ill., Mo., Ky., Tenn., Ark., Miss., La. Two flood control projects
7. Big Sandy River W.Va., Ky. Water pollution from coal mining accident
8. Snoqualmie River Wash. Residential, business development in watershed
9. Animas River Colo., N.M. Water diversion project
10. East Fork, Lewis River Wash. Gravel mine expansion
11. Paine Run Va. Acid rain from coal-fired power plants
12. Hackensack River N.Y., N.J. Residential, business development
13. Catawba River N.C., S.C. Development along banks