Here’s the webpage from American Rivers. Here’s the 2012 list:

#1: Potomac River (MD, VA, PA, WV, DC)
Threat: Pollution
At stake: Clean water and public health

#2: Green River (WY, UT, CO)
Threat: Water withdrawals
At stake: Recreation opportunities and fish and wildlife habitat

#3: Chattahoochee River (GA)
Threat: New dams and reservoirs
At stake: Clean water and healthy fisheries

#4: Missouri River (IA, KS, MO, MT, NE, ND, SD, WY)
Threat: Outdated flood management
At stake: Public safety

#5: Hoback River (WY)
Threat: Natural gas development
At stake: Clean water and world-class fish and wildlife

#6: Grand River (OH)
Threat: Natural gas development
At stake: Clean water and public health

#7: South Fork Skykomish River (WA)
Threat: New dam
At stake: Habitat and recreation

#8: Crystal River (CO)
Threat: Dams and water diversions
At stake: Fish, wildlife, and recreation

#9: Coal River (WV)
Threat: Mountaintop removal coal mining
At stake: Clean water and public health

#10: Kansas River (KS)
Threat: Sand and gravel dredging
At stake: Public health and wildlife habitat

From The Salt Lake Tribune (Brett Prettyman):

The report, by American Rivers, places the Green River at No. 2 on its list of America’s Most Endangered Rivers of 2012.

The greatest threat to the river — which meanders about 730 miles from its headwaters in the Wind River Range in Wyoming through Utah, Colorado and back into Utah where it ends in a confluence with the Colorado River in Canyonlands National Park — is the proposed Million pipeline, says the report. That project would pump more than 250,000 acre-feet of water from the Green River 500 miles across Wyoming to the Front Range area of Colorado. While the Federal Energy Regulatory Commission rejected the proposal in February, developer Aaron Million requested a rehearing of the plan.

“Water in the West is critical to more things than just fueling speculative urban growth,” said Nathan Fey, director of American Whitewater’s Colorado River Stewardship Program. “While the Green River is viewed as a solution to Colorado’s future water shortage, the river today supports a diverse economy, sustains rare wildlife and endangered fish populations and offers unique opportunities for people to experience how water interacts with the landscape.”[…]

Wyoming Gov. Matt Mead has said the proposed pipelines are not a responsible use of taxpayer money. American Rivers, an organization dedicated to protecting and restoring the nation’s rivers and streams, wants to see Herbert and Colorado Gov. John Hickenlooper join Mead in defense of the Green River.

[Utah Governor Gary Herbert] in January said his staff was following the Million pipeline issue closely, but Utah political leaders have not taken a formal position. American Rivers said polls in Utah and Wyoming have revealed the pipeline project is “extremely unpopular among the public.”

More Green River basin coverage here.