Update, 7:05 p.m.: Authorities confirmed Monday night that the cause of the Saddle Butte Fire was a bundle of Mylar balloons that became tangled in power lines causing an electric arc.

"An unusual accident is ruled the cause of Jackson’s second and largest wildfire of the year," a news release states. 

The Jackson Police Department, Jackson Hole Fire/EMS and Bridger-Teton National Forest conducted interviews, took witness statements and investigated the site.

After the balloons hit the lines, the release states, "flaming materials fell to the ground and ignited dried grasses below the power lines and poles. Strong winds and steep slopes caused the fire to accelerate rapidly up the butte."

Incident Command estimates that the fire is 50-60% contained.

“Ground crews and air resources made good progress today,” said Incident Commander Dave Wilkins in a statement. “We were encouraged to see that fire containment lines held throughout the day with strong winds, low humidity and warm temperatures.”

Residents in the Saddle Butte Subdivision remain evacuated overnight as crews continue to monitor the fire. 

Update, 5:20 p.m.: News&Guide staff have added a "Saddle Butte Fire — By the numbers." See sidebar column.

Update, 2:10 p.m.: About 30 homes in the Saddle Butte subdivision will remain evacuated overnight, according to Teton County Public Information Officer Kristen Waters.

Authorities allowed evacuees to visit their homes to grab medication and pets this afternoon.

Air attacks are still underway, according to Town of Jackson Public Information Officer Carl Pelletier. 

"They're being aggressive in regard to holding the line," Pelletier said. 

Three helicopters began bucket drops at 9 a.m. and were expected to continue throughout the day. Roughly 100 people are assigned to fighting the fire.

Update, 10:10 a.m.: A transformer near Budge Drive blew, starting a small fire that was quickly extinguished by bystanders with garden hoses.

Apartments near the transformer have lost power.

Original story, 10 a.m. Monday: With red flag conditions predicted for the afternoon of Labor Day, firefighters are working quickly to secure the perimeter of the Saddle Butte Fire before the weather turns against them.

Fire behavior slowed Sunday evening as wind died down, slurry and water knocked down flames and temperatures cooled. The fire, which began around 1:25 p.m. Sunday near an electrical transformer, burned about 250 acres from the southern base of East Gros Ventre Butte up to the top, along the peaks and around the edge.

“We don’t consider the fire to be contained yet,” Jackson Hole Fire/EMS Chief Brady Hansen said at 9:30 a.m. Monday. “Right now while it’s cool the fire has really laid down, is really benign, but our experience tells us by 2 p.m. today with red flag conditions the fire will pick up and start racing again.”

Time is of the essence, and about 80 people are working to build and hold a line around the fire before hot winds hit the embers this afternoon. Hansen from Jackson Hole Fire/EMS and Dave Wilkins from the Bridger-Teton National Forest are sharing command of the operation with support from two hotshot crews and Grand Teton National Park, among other agencies.

“If we don’t get the perimeter controlled then today will look like yesterday,” Hansen said. “There’s a lot of hot embers in there that’ll take off as soon as red flag conditions hit it.”

Saddle Butte subdivision remains evacuated. About a dozen firefighters babysat the fire overnight, using water lines and keeping an eye on structures in the subdivision as hot spots burned. No large structures have been lost, although the fire may have damaged other items like a shed or trailer.

Fire managers are optimistic that the hard work done in the evening and morning hours will help keep the fire controlled when the weather turns.

“When the wind’s blowing hot it’s like trying to stop a tidal wave,” Hansen said. “When the wind is calm that’s our chance.”

Helicopters, air tankers and ground personnel are working the fire today. Highway 89 at the northern edge of Jackson may be closed intermittently so helicopters can access Flat Creek with water buckets. Hansen said he has requested additional resources from Sublette County and from Teton County, Idaho, but feels good about the number of bodies attacking the blaze.

Bradly J. Boner contributed to this report.

Share your stories with us. Contact editor@jhnewsandguide.com.

Contact Johanna Love at 732-7071 or jlove@jhnewsandguide.com.​

Johanna Love steers the newsroom as editor. Her time off is occupied by kid, dog, biking, camping and art. She loves to hear from readers with story tips, kudos, criticism and questions.

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(2) comments

Terry Milan

Plastic bags used to carry groceries, not OK. Plastic balloons frivolously launched, OK.

Susan Crosser

This would be a good time to explain why you should NOT release balloons to drift away in the sky. No matter how pretty it looks, it can affect wildlife, and if they come in contact with overhead lines - fires.

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