High temperatures and low humidity prevented firefighters from extinguishing a fire Saturday that threatened at least two dozen homes in a small town in central Utah, AP reported. 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 (72.5-square-kilometer) fire about 10 miles (16 kilometers) east of the town of Indianola. Temperatures were expected to reach 100 degrees Fahrenheit (38 degrees Celsius), 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 (137 kilometers) 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 (51.5-kilometer) 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. The United States' 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. As of late Friday, more than 20,000 firefighters were fighting fires burning an estimated 1,950 square miles (5,050 square kilometers) in 11 states, said Henri Bosson, the U.S. Bureau of Land Management's deputy director for operations. Nearly one-fourth of that land area _ about 450 square miles (1,165 square kilometers) _ 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.» Almost half the 72 large fires burning nationally are in Nevada and Idaho.