'Most Endangered River' in the United States: the Colorado River in the Grand Canyon

The American Rivers advocacy group has released its annual list of America's Most Endangered Rivers, which highlights ten rivers "facing urgent threats, and encourages decision-makers to do the right thing for the rivers and communities they support."

Topping the list is the Colorado River in the Grand Canyon—arguably among the most famous stretches of river in the country. According to the American Rivers website, "[a] proposed industrial-scale construction project in the wild heart of the canyon, radioactive pollution from uranium mining, and a proposed expansion of groundwater pumping at Tusayan, all threaten the Grand Canyon’s wild nature and unique experience that belongs to every American."

The following rivers comprise the complete top ten:

1. Colorado River in the Grand Canyon
2. The Columbia River in Washington and Oregon
3. The Holston River in Tennessee
4. The Smith River in Montana
5. The Edisto River in South Carolina
6. The Chuitna River in Alaska
7. The Rogue and Smith Rivers in Oregon and California
8. The St, Louis River in Minnesota
9. The Harpeth River in Tennessee
10. The Pearl River in Louisiana and Mississippi

Stephanie Hemphill picked up the news of the St. Louis River's inclusion on the list, noting that the river is the largest U.S. tributary to Lake Superior and include on the list due to plans for copper-nickel mining at its headwaters.

The entire 2015 report is available in pdf form.