Twin Falls and the Magic Valley seems to be choked with smoke today (Sep. 18), but where is it coming from?

From the Idaho Department of Environmental Quality's Smoke Forecast:

Smoke from fires in California and Oregon are bringing smoke through the Snake River Plain as far east as Twin Falls; however, smoke is forecast to drain into the Upper Snake via the Lemhi Valley and the eastern Lost River Range. Smoke from fires burning in Washington and Oregon will be transported into the Panhandle and Central regions, respectively once more this afternoon.

You can check the latest Smoke Forecast at the Idaho Department of Environmental Quality site.