Three wind-whipped wildfires in hot, dry northern Utah Saturday stretched fire crews thin and in one case required campers and horseback-riders to evacuate, officials said.

The fires were located in Summit, Tooele and Utah counties and spread fast throughout the afternoon, aided by 15- to 25-mph winds. The National Weather Service in Salt Lake City issued red-flag warnings as high temperatures and winds Saturday created severe fire-weather conditions over most of the state. Those warnings were to remain effective through Sunday night.

"If anything's going to spark today, it's going to burn," Erin Darboven, fire information officer for the Bureau of Land Management's Salt Lake field office, said Saturday.

• A fire sparked just before noon north of Cedar Fort in Utah County and had grown to about 700 acres by 8 p.m., Utah County Sheriff's Lt. Darren Gilbert said. Flames shot up to 60 feet high and crept up ridgelines, nearing the area of six cabins — including one historic structure — in West Canyon, he said.

Deputies closed West Canyon Road to make way for fire traffic and keep people from wandering too near the fire. A few people were allowed through to remove their animals, Utah County Sheriff's Sgt. Spencer Cannon said.

"There were a number of campers in there, a number of horseback-riders," Gilbert said. "We believe we have everyone out of the canyon."

Crews from agencies including the state, U.S. Forest Service, Salt Lake County, Lehi, Saratoga Springs, Eagle Mountain, Utah County, Cedar Fort and the BLM responded to the blaze, Gilbert said. "About 60 people are on the line, up from 40 earlier."

Camp Williams assisted from the air with Blackhawk helicopters equipped with 500-gallon water tanks; an airplane was dumping fire retardant in the early evening, Gilbert said.

The fire was expected to be contained Monday afternoon, Darboven said.

"We're asking for more resources, but there are a number of other fires going on in the state," Gilbert said. "It's getting somewhat difficult because of those other fires."

The fire started when a model rocket ignited brush, Cannon said. Smoke was visible from parts of the Salt Lake Valley, prompting several calls to 911 dispatchers.

"The smoke, it's made some residents nervous," said Shirl White with the Unified Fire Authority. "The way the winds are, they're worried about (embers and ashes) kicking up and dropping here."

A second, smaller fire popped up south of Cedar Fort, but firefighters had the blaze mostly under control Saturday afternoon.