As Canada grapples with one of its worst wildfire seasons on record, smoke from the blazes have prompted air quality alerts across the U.S.

Wildfires raging across remote areas of northwest Canada are proving nearly impossible to contain, according to the Times Union. With more than 200 active fires, many in roadless, unmanaged forest, Canadian firefighters remain overwhelmed—leaving much of the Northeast,

Hundreds of wildfires still burning in Canada are expected to undermine air quality across the Upper Midwest and Northeast into Tuesday.