Smoke from the Rim Fire that's burning out of control on the mountain rims of the Stanislaus National Forest has stretched more than 200 miles.
Photos released by NASA show the smoke is making a beeline straight to Reno, Nev.
School officials canceled all outdoor activities in Carson City, Washoe and Douglas counties because of the smoke.
One person who lives in Reno said the sky made him feel like he was living on Mars. A thick haze has blanketed the city.
The smoke forced Reno health officials to issue a warning about the air quality. The Washoe County Health District says the air quality index pushed into the red, unhealthy zone Friday with a peak reading of 166.
Officials issued an initial alert Thursday for sensitive populations when the index surpassed 100. The 150 level triggers the red alert indicating even people without respiratory conditions may be affected.
There are also reports of ash falling in and around Reno.
Smoke from the fire is also reported in Lake Tahoe.
Tahoe's South Shore is getting hit by two fires. It is also getting smoke from a separate fire, the American fire, which began Aug. 10. That fire has scorched nearly 17,000 acres.
The Rim Fire has now burned more than 100,000 acres. It nearly doubled in size for the second night in a row. The fire crossed into Yosemite National Park overnight, although it is a long way from threatening the famed Yosemite Valley.
Yosemite remains open, but the wildfire caused the closure of a 4-mile stretch of State Route 120, one of three entrances into the park on the west side.