The Fish and Wildlife Service is reintroducing Mexican wolves in Arizona and New Mexico, part of their original range.
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The wildlife refuge's past as a Superfund site has caused concern among environmental groups.
New research from CU Boulder analyzed weather and crime data from 16,000 cities.
Starting Jan. 1, there will be varying increases to state licenses and annual park passes.
In 1991, federal officials classified the razorback sucker as an endangered species.
The Fish and Wildlife Service is expected to announce that the wolves have recovered sufficiently to be removed from the Endangered Species Act.
President Trump has said he will roll back an Obama-era rule that would've matched federal emissions standards with California standards.
It's a wholesome, very Colorado activity worth making a family tradition. It does, however, take a little bit of planning before you head out.
In coffee shops around Boulder, customers can now get their drinks in a free, reusable cup that they can then return.
The EPA wants to roll back a 2016 Obama-era rule that required energy companies to step up detection and elimination of methane leaks.
County officials had been concerned that there would have been an influx of permits if the ballot measure had passed.
Even with a newly-minted trifecta control of the levers of government, Democrats will face roadblocks.
Polis made one of his first public appearances as Colorado's governor-elect at the Outdoor Retailer Winter Market.
Climate change is pushing polar bears from the sea to land. Joel Berger wants to find out how the oxen will respond to this potential predator.
The land was in big game habitat and the North Fork Valley in western Colorado.