OGDEN -- Three fires burning several thousand acres in central Utah are pumping a lot of smoke into the air, but fires in Idaho are making the mountains in Top of Utah disappear.
Mount Ogden was invisible from Business Depot Ogden by 2 p.m. Monday as the smoke levels slowly rose.
Bo Call, air quality monitoring supervisor at the Utah Division of Air Quality, said the air pollution was mostly smaller particulate matter and "looks worse than it is," but said the concentration was rising as the day went on.
The Division of Air Quality rated the air quality Monday afternoon as "moderate," meaning those with lung problems and the elderly should restrict outdoor activity.
"It came from our friends to the north," Call said of the smoke in the air. "Pretty much, it's coming out of Idaho. They've got a bunch of fires up there, and its blowing this way, and down here in Salt Lake we've got it coming both directions."
The fires Call referred to in central Utah include one near Dugway that started Monday morning and had already burned 1,000 acres of dry grass.
Cami Lee, at the Utah Fire Information center, said the Butte Fire was discovered 8:55 a.m. Monday southwest of Simpson Springs near Dugway. She said the cause is still being investigated and no firefighting resources had been used on it as of Monday afternoon.
She said no structures had been threatened by the fire.
The West Lake Fire, 8 miles north of Genola, was expected to be contained Monday evening after burning more than 600 acres. That fire started Saturday and is being blamed on sparks from target shooters.
A third, the Tank Fire in American Fork Canyon, was caused by lightning and had burned only 25 acres since it was discovered Sept. 2. The U.S. Forest Service said it was unable to get firefighters to it because of the steep hillsides and was monitoring it, using helicopters to dump water on hot spots as needed.
The National Weather Service issued air quality alerts for southern Idaho because of the smoky air, but nothing for Utah as of Monday afternoon.
The fires causing the smoke were clustered in the north-central part of Idaho and were all very large.
The Trinity Ridge fire, in Elmore County, was nearly 150,000 acres, for example. The Halstead Fire in Custer County was more than 160,000 acres, and the Mustang Complex fire in Lemhi was more than 320,000 acres.
Call said he couldn't predict when the smoke would clear out.
The National Weather Service is predicting eastern winds up to 9 mph this morning, easing off this afternoon.
Wednesday will see winds of about 6 mph out of the south, which could replace smoke from the Idaho fires with smoke from the Utah fires.