TUCSON, Ariz. — Crews on Saturday worked to protect several small Arizona communities from two large wildfires by clearing away brush near homes and planning to set fires aimed at robbing the blazes of their fuel.

The Wallow Fire, near the White Mountain community of Alpine, grew to 218 square miles, or more than 140,000 acres, by Saturday morning.

The fire is the third largest in state history, with its smoke visible in parts of southern Colorado. Fire officials said they had zero containment of the fire near the New Mexico-Arizona state line, which has forced an unknown number of people to evacuate.

The fire has burned four summer rental cabins since it started May 29, the U.S. Forest Service said.

Crews were working to protect homes in Alpine and nearby Nutrioso from the fire and blowing embers that could start smaller, spot fires. The fire had reached Alpine's outskirts and was about two miles away from homes in Nutrioso, said Bob Dyson, a spokesman for the team fighting the blaze.

A shift in winds around midafternoon Saturday blew embers that started a spot fire at the southwestern corner of Alpine. A helicopter knocked down that fire by dumping water on it, and no buildings were damaged or destroyed as a result.

The yellowish smoke in Alpine was so heavy that it reduced visibility to about a quarter mile.

Authorities Friday night warned residents of the town of Greer to be ready to leave, but no evacuation order has been issued. Greer has fewer than 200 permanent residents, but the town and area attract many vacationers.

Gov. Jan Brewer traveled to Springerville to get a briefing from fire team's commander and took an aerial tour of the blaze to get an appreciation for its scope and size, said Matthew Benson, a spokesman for Brewer.

"The governor's main concern is for the families living in the White Mountains and the firefighters and emergency personnel responding to this fire," Benson said. "It's an extremely dangerous fire at this point."

In terms of size, the Wallow Fire ranks behind Arizona's 469,000-acre Rodeo-Chediski Fire in 2002 and the 248,000-acre Cave Creek complex fire in 2005.

Meanwhile, crews were trying to protect a church camp and two communities from the Horseshoe Two fire that had burned 140 square miles in far southern Arizona. It's the fifth-largest fire in state history.

The 90,000-acre blaze had come within a mile of the evacuated Methodist church camp in the steep Pine Canyon near the community of Paradise on Friday night.

"It will be a major concern until the fire passes there," Dave Killebrew, a spokesman for the team fighting the fire.

Helicopters were dumping water and retardant on a hotspot near the camp. "As far as I know, (the fire) hasn't gotten into the camp," Killebrew said Saturday.

Crews also were focusing on protecting the evacuated communities of Paradise and East Whitetail Canyon. Paradise fared well Friday as crews set fires that burned natural forest fuels and kept the blaze from about a dozen occupied homes and many other vacation residences.

The fire was within two miles of the eight to 10 homes in East Whitetail Canyon. The blaze is 50 percent contained.

The nearby Chiricahua National Monument was closed as a precaution.

The Horseshoe Two fire has been burning since May 8 and about 800 firefighters were battling it.