A giant smoke cloud hovered over the Catalina Mountains north of Tucson on Wednesday as the Bighorn Fire moved through dense fuel as it crept closer to the western edge of the Summerhaven community.

The smoke in the Summerhaven area was caused by the fire’s movement northwest of Mount Lemmon SkyCenter Observatory, said Rocky Gilbert, an operations section chief for the Southwest Incident Management Team.

More than 800 people are fighting the fire, which has grown to 31,208 acres and is at 40% containment as of Thursday morning. Upwards of 400 firefighters were in the Mount Lemmon area on Wednesday. 

It has cost about $10 million so far to fight the Bighorn Fire, officials said. That cost is mainly due to the need to use aircraft to fight the stubborn fire in areas unreachable by ground crews.

Fire crews conducted a successful burnout operation overnight Tuesday in the Summerhaven community and around the observatory to keep the fire from reaching those areas, Gilbert said.

Firefighters were set to conduct another burnout operation Wednesday night from the observatory north down toward the town of Oracle to keep the fire from moving back uphill toward the observatory and Summerhaven area, Gilbert said.

As of Thursday morning, no structures in the Summerhaven community have been lost. 

“I do want to point out that we still have quite a bit of active fire to the south and west of the community, though, that we’re still very concerned about,” said Travis Mabery with the Southwest Incident Management Team. He added that “by no means is the threat over to that community.”

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The fire also started moving across the Samaniego Ridge, fueled by the wind and large amount of brush and fuels, which is also causing heavy smoke visible from the west side of the fire, Gilbert said.

Because the fire along Samaniego Ridge isn’t threatening any structures, there are no fire crews along the ridge line.

Crews are working to the north end of the fire reconstructing fire lines used in the 2003 Aspen fire, Gilbert said. They are also working on fire lines to the east, along Loma Linda northeast of Summerhaven.

“Right now we’ve got a good plan in place,” Gilbert said. “The values at risk that we’re dealing with are protected and we’ll continue to reinforce that and be ready for a fire if it moves into any of the communities.”

An evacuation order was issued Tuesday for parts of Mount Lemmon including Summerhaven and Mount Bigelow. The evacuation order remained in place Wednesday.

On Tuesday night, Pima County Sheriff Mark Napier said all but six of the residents in the evacuation area voluntarily left the mountain.

“Six people indicated that they would shelter in place,” Napier said. “We certainly warn against it just because if the fire behavior changes and becomes much more aggressive or quicker we are not going to be able to go in to save those people who decided to shelter in place.”

Napier said he wasn’t sure Wednesday whether those residents had changed their mind.

Evacuation alerts for the Oro Valley area from Catalina State Park south to West Magee Road and the Tucson Foothills area from North First Avenue east to North Alvernon Way, which were formerly on “set,” were downgraded to “ready” Wednesday.

The fire lines in those two areas to the west and southwest of the fire have not moved in days, officials have said.

Residents who evacuated their home in those areas can return but are asked to be vigilant, the Pima County Sheriff’s Department said.

A red flag warning was in place Wednesday as less than 15% humidity combined with winds stronger than 20 mph.

The wind is expected to continue through Thursday before moving out of the area and being replaced with higher temperatures near 107 degrees in Tucson, said Gary Zell, incident meteorologist for the fire and National Weather Service meteorologist in Tucson.

A Chinook helicopter drops water on a ridge above Pima Canyon in Coronado National Forest during the Bighorn Fire on June 10, 2020. Video by Rick Wiley / Arizona Daily Star

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