A short stretch of the river drops into a narrow channel that allows to run deeper, faster and colder.
The US and Mexico signed a new agreement to share water from the Colorado River, and improve conservation in Mexico, particularly on farms.
The agreement includes spending millions of dollars on conservation projects and drawing up plans to deal with drought and climate change.
The EPA is installing a barrier at the mine outside Silverton to prevent another spill like the one in 2015 that sent 3 million gallons of toxic water into rivers.
Millions of people rely on crops and cattle that feed off the aquifer. As streams dry up, conservation becomes key.
Overall, the river serves more than 40 million people in cities, farms and tribes in Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming. Mexico also gets a share.
Utah wants cleanup compensation and unspecified damages in the 3-million-gallon Gold King Mine spill that was accidently triggered by EPA contractors.
"The Air Force does not have the authority to reimburse communities for costs incurred in dealing with environmental contamination issues.
The agency started work on safety standards after the spill and expects to soon finish them, investigators from the EPA's Office of Inspector General said.
Farmers are getting paid not to plant for part or all of this season. Water managers hope the pilot program will help them prepare for drought in the future.