Smoke across the U.S.

There is so much smoke from so many sources that it is becoming difficult to determine the origin. Today's smoke map generated by NOAA is very different from the one yesterday. The visibility here in South Dakota is about two miles due to smoke. I just talked with someone in Billings, MT and he said it is about the same there.

So you tell me. Is the smoke in South Dakota coming from the fires in California, or Canada? It seems unlikely it could be coming from both, as the map seems to indicate. Maybe the California smoke is blown to the north occasionally, then later a west wind blows that plume to the east.