Looking at the NOAA HMS Smoke and Fire Product (top left), the small red dots indicate groups of fires, while the light grey areas are smoke plumes. The one across the Northern Plains are a result of agricultural burns in Canada, similar to Friday. The MODIS Terra image (top right) shows raised AOD values in the South, however, particularly the Gulf of Mexico and Texas.
The webcam photo to the left is from Big Bend National Park, TX at 3:45 CDT. The visual range is unavailable, although it is clear that air visibility is diminished significantly. The comparison photo (middle right) has a bad visibility example, and it looks that today's air quality is even worse than that. Ray Hoff mentioned this weekend of blowing smoke over much of the Southwest, and this could very well be a factor affecting air quality in this region today.
The EPA AIRNow combined AQI animation below also shows good AQIs over much of the United States for today, with moderate AQIs seen around the eastern portion of Texas, near where Big Bend National Park is located. Moderate AQIs were prevalent over much of the East Coast as well, with even small areas of USG AQIs popping up sparingly throughout the day. The current high AQI goes to Susquehanna Valley, PA (97).