Colorado

Polis signed SB 26-189 on May 14, repealing the duty of care, impact assessments, and risk management mandates of SB 24-205 in favor of an ADMT notice-and-explain regime taking effect January 1, 2027.

Colorado, California, and Oregon are all enforcing or adopting wildfire-resistant construction standards in 2026, though municipal capacity and cost concerns threaten to slow the rollout.

Paleontologists have recovered tiny fossilized teeth of Purgatorius from Colorado's Denver Basin, marking the southernmost occurrence ever documented and suggesting that archaic primates dispersed rapidly across western North America within hundreds of thousands of years of the dinosaur extinction.