The nation's firefighting preparedness has moved to its highest level this week, and officials worry that the worst is to come with forecasts of more lightning and extremely dry conditions.
Nearly one-fourth of that land area — about 450 square miles — was burning in Nevada.
"We are seeing continued drying. We're seeing heavy fuels in the higher country — a lot of grass and dry brush in the lower country," Bosson said.
"And we expect that we are going to be seeing a lot more lightning over the next few weeks so we are very, very concerned about the situation. ... We are just now entering what would now be considered the traditional fire season."
The fires are so bad in northern Nevada that volunteer firefighters from the south of the state left for northern regions this morning to provide some much needed support to firefighters who have been battling wildfires for more than a week, reports CBS News affiliate KLAS-TV in Las Vegas.
"The firefighters need a break, so a fresh crew is coming up," said volunteer firefighter Danny Rowlett.
Almost half the 72 large fires burning nationally are in Nevada and Idaho. A fast-moving, 239-square-mile fire near Jarbidge, Nev., and Murphy Hot Springs, Idaho, forced the evacuation of the tiny towns about 15 miles apart.
High temperatures and low humidity are also a problem in Utah, where firefighters battle to extinguishing a fire Saturday that threatened at least two dozen homes in a small town in the central region of the state.
Fire crews were waiting for more firefighters to arrive so they could work to extinguish the fire rather than just protect cabins, homes and trailers threatened by the 28-square-mile fire about 10 miles east of the town of Indianola.
Temperatures were expected to reach 100 degrees, and humidity was forecast to be about 10 percent Saturday in many areas where the Utah's 10 wildfires were burning.
The blaze began Thursday in a private campground in Salt Creek Canyon, 85 miles south of Salt Lake City. A motel and some vehicles and trailers were burned, the U.S. Forest Service said.
The fire had forced several evacuations and rescues along a 32-mile scenic road in the Uinta National Forest since Thursday.
The cause was still being investigated Saturday, but initial reports suggested a motorist may have sparked the fire by riding on the rim of a flat tire on a highway that is an access route to the forest.