Saturday's smoke generated from the nearby fires in the Shasta-Trinity and Six Rivers National Forests can be seen in the satellite image below drifting to the west and north. Some of the smoke monitoring sites in the deep river valleys are shown on the image on the right.
A mid-day peak in smoke concentrations is displayed in the graphs below. The morning began in most valley locations with relatively clean air with a layer of smoke above the valley. Daytime heating mixed the smoke down to the surface between 10 am and noon, then the valleys began to clear again in the afternoon with the exception of Orleans, which was north of the most active fires and excerienced a second peak in concentration.
Satellite image from 4:45 pm PDT 8/22/15 Smoke monitoring sites and wildfire perimeters