Smoke triggers pollution alerts in US West, Midwest

Air quality alerts were posted on Sunday for numerous areas of the U.S. West and Midwest as wildfire smoke continues to linger over much of the country

DENVER -- Numerous areas of the U.S. West and Midwest were under air quality alerts on Sunday as wildfire smoke lingered over much of the country.

Alerts were in place across much of the northern U.S. Rockies, including portions of Colorado, Wyoming, Washington state and Idaho.