Up before the sun, CU grad students Neil Stewart Ben Miller walk along a remote stretch of cold water.
"The insect diversity is a good indication of a rivers health," Miller said.
They only found one kind of insect, which is a good sign this part of the river is not healthy and has a high concentration of metals in it.
"Metals are toxic to most fish and insects," Miller said.
Metal from rocks naturally seep into this river, which runs red at the headwaters.
But, in recent years the metal count here has been on the rise.
"When you have low water flows, you're still getting the same amount of metal," Stewart said. "But, you're having higher concentrations."
Lower water flows and higher temperatures drawing more metals out of rocks and into the water could be to blame.
"That more or less exasperates the effects of this naturally occurring phenomena," Stewart said.
The water is diluted long before it reaches Lake Dillon and becomes drinking water. However, scientists like Stewart are still concerned to see higher metal concentrations in the river.
"You can see how the climate effects here can be applied to other locations," Stewart said.
Rising temperatures in rivers in the future could have long term effects on aquatic life and the very water we drink downstream.