Guard officials said Tuesday they were working to both keep the flames within Camp Williams' boundaries, and specifically away from a remote artillery training "impact area" that may have unexploded ordnance on site.
"Sometimes the rounds explode, no issues. Sometimes they don't," said Lt. Col. Hank McIntire.
He explained it is the duds they are concerned about. "When fire goes through that area, that becomes a concern."
Senior Master Sgt. Daniel Morbach, an explosive ordnance disposal expert, said that since the range has been around since the early 1900s there are hundreds to thousands of artillery shells lying around ranging from small bullets to others 8 inches in diameter.
"This is a live range," Morbach said. "The risky part is the shrapnel."
If a large artillery shell explodes it can scatter shrapnel up to a mile. Morbach said that is why firefighters are taught to report any sightings of shells. So far there have been two, but both were already discharged.
"We are asking them to keep a close eye and if they see something to back out," he said.
Oversight of the firefighting efforts Tuesday was turned over to a Type III Incident Management Team. Spokeswoman Kim Osborn said additional resources were being mustered to turn the tide on the Pinyon Fire. During the day Blackhawk helicopters dropped about 120 buckets 600 gallons each of water on the blaze.
She said three new crews, including one from Alaska, were being brought in, bringing the total of Guard, Utah County, municipal and federal firefighters attacking the blaze to more than 200. In addition, several water-bearing helicopters and fire retardant-laden air tankers joined the fight.
"We're going to try to keep this fire contained within the Camp Williams area. We'll have a lot of firefighters out today and we hope to do some good work," she said.
Late Monday, authorities invited those who could not find accommodations with friends or family to spend the night at a shelter set up at Rockwell Charter High School, while large animals were given refuge in Eagle Mountain's rodeo area. Twenty-seven people spent the night at the shelter overnight, 14 of them inside the school and 13 outside in campers and RVs, Eagle Mountain spokeswoman Linda Peterson said.
However, officials deemed the threat to homes in the area over by late Tuesday morning, announcing the evacuation order was being lifted.
By Tuesday afternoon a caravan of evacuee trucks hauling trailers and cars made an uninterrupted drive from the school back to their homes in the North Ranch subdivision.
Tom and Marsha Worlton unleashed their 10 prize-winning Lhasa Apso dogs first thing when they returned home. "This was our number one priority getting these animals out," Tom said as his pets barked with excitement after spending the night in an RV and kennels outside the shelter.
"It feels really good," Worlton said about being back but added, "We will keep the kennels handy. We will stay prepared until this [fire] is contained."
Jared and Leslie Jones didn't even plan on evacuating until family in Lehi became concerned for them, so they packed up a few things and spent the night with them. By Tuesday afternoon, they had unpacked and returned home and were busily attending to their dry garden.
"We didn't really feel threatened," Jared Jones said while watering plants.
The evacuations came after winds kicked up the flames throughout Monday afternoon in tinder-dry sagebrush, grass, juniper and pinyon fuels.
Eagle Mountain Mayor Heather Jackson said people were being allowed back to their homes Tuesday because although flames late Monday had burned within 600 feet of some homes, "the most active fronts of the fire" were contained to the Camp Williams area.
Regarding other Utah wildfires, the:
• Pine Canyon Fire near Grouse Creek in Box Elder County has burned nearly 400 acres. There was no estimate Tuesday for when it would be fully contained.
• Pumpkin Fire, burning 20 miles east of Spanish Fork in Utah County, was declared 100 percent contained Tuesday afternoon after burning nearly 200 acres, according to Fire Information Officer Loyal Clark.
• Pyramid Fire in Iron County, northwest of Enterprise, was fully contained Tuesday afternoon after burning 51 acres. The fire was sparked by lightning Sunday afternoon.
• West Mountain Fire in Washington County had burned near 2,500 acres but was 75 percent contained. Crews continued to monitor flames that had earlier threatened radio towers, but no evacuations had been ordered and no injuries were reported.