While the smoke is worst along the Western Slope where the fires are burning, levels are also fluctuating on the Front Range.

Air quality alerts are in effect on Tuesday in 10 states as toxic smoke from hundreds of wildfires burning in Canada ...

On Tuesday at 8:20 a.m. the National Weather Service reported an air quality alert in effect until 11 p.m. for Passaic, ...

An air quality alert was reported by the National Weather Service on Tuesday at 9:10 a.m. in effect until 11 p.m. for Western ...

An air quality alert was reported by the National Weather Service on Tuesday at 12:17 p.m. in effect until 8 p.m. for ...

The National Weather Service reported an air quality alert at 12:43 p.m. EDT on Sunday in effect until Tuesday at noon EDT ...

Despite thick smoke in the sky today in southern Colorado, air quality alerts haven't been issued - instead they've been in the western slope. In fact - sometimes invisible compounds pose more risk.

OLYMPIC NATIONAL FOREST, Wash. — The Bear Gulch Fire within the Olympic National Forest and National Park has now prompted an ...