The Chinchaga firestorm's "historic smoke pall" caused "observations of blue suns and moons in the United States and Europe".

One version faults an Imperial Oil surveying crew with starting a small blaze to protect their horses from biting insects.

The ignition point was north of Fort St. John, British Columbia, and the fire burned north-eastwards nearly to Keg River, Alberta.

A series of high pressure systems over the summer allowed a buildup of heat and dry air, reducing the moisture levels in the forest fuels.

[8] Size estimates vary due to its remoteness from population centres and the imprecise measurement techniques of the time period.

[5] In 2008 and 2009, researchers with Natural Resources Canada and the University of Victoria conducted airborne surveys of several boreal forest fires, including the Chinchaga.

The timber of the Chinchaga River watershed had not been surveyed and was undervalued by the Alberta provincial government, which placed the fire's cost at one million dollars.

At the time, the Alberta forestry department's policy was to respond only to fires within 16 kilometres (10 miles)[10] of settlements and major roads.

[14] The towns of Sarnia and Guelph experienced three-hour midday periods of darkness, streetlights in Toronto turned on by themselves, and drivers resorted to using their automobile headlights during daytime hours.

Explanations included nuclear armageddon, local fires, secret U.S. military experiments,[16] an American atomic bomb blast,[15] supernatural forces, a solar eclipse, and an alien invasion.

New York, Pennsylvania, Ohio, Washington D.C., Virginia and Florida all reported effects from the fire, especially on September 24, so called "Black Sunday".

In early October, a smoke observation was made on the Aleutian Islands, suggesting that the Chinchaga haze had possibly circled the entire globe.