The smoke flowing into Reno, Carson and the Tahoe Basin is still thick Friday morning and in some places visibility is down to a mile. That smoke is coming from the Rim Fire burning near Yosemite National Park, which tripled in size yesterday. It currently stands at about 165 square miles with only 2 percent contained so far.
http://www.kunr.org/news/smoke-expected-through-the-weekend-in-western-nv-and-the-sierra