Colorado ranks 21st in the United States when it comes to being environmentally friendly, that according to the website WalletHub, which released a study on Monday about the most environmentally friendly states. The website did rank Colorado as the No. 1 state when it comes to having LEED-certified buildings. Several of those energy-efficient buildings, including those at the University of Northern Colorado, were in Greeley. WalletHub said it considered the following factors when measuring each state from an environmental standpoint: Environmental quality; eco-friendly behaviors and climate-change contributions. Colorado ranked fifth when it comes to water quality. The state that is best for the environment? Well, that would be Vermont. To view the full article visit the Greeley Tribune.