High Wind in Montana, December 17, 2025

Extreme gusts battered Sanders and Mineral Counties on December 17, with peak wind reports including 69 mph at 0800MST at the Plains AWOS and 57 mph at the Thompson Falls RAWS. The dangerous conditions prompted an urgent Do Not Travel alert from the Community Ambulance Service of Western Sanders County at 0830MST because live power lines and falling trees completely blocked roadways. Major transportation corridors were heavily impacted: a downed tree blocked a lane of I-90 Westbound at 0725MST, fallen trees blocked the Eastbound I-90 Tarkio exit at 0845MST, a semi-truck crash completely blocked MT-200 at 0940MST, and downed power lines forced the closure of Highway 10 West near Huson at 1120MST.

Utility infrastructure suffered catastrophic damage from falling timber. In Mineral County, over 80 percent of tracked customers (4,002 meters) lost power. Sanders County experienced similar devastation, with 4,481 customers, roughly 47 percent of the county, losing electricity. The power outages were so widespread and prolonged that approximately 250 residents utilized a warming shelter in Mineral County two days after the initial event. High-elevation recreation was also impacted, with Lookout Pass Ski Resort losing power by 0735MST, alongside reports of widespread timber blowdowns across its ski runs.

Structural and property damage was severe and widespread across the zone. At 0930MST, severe winds ripped sections of the roof off Thompson Falls Elementary School. In Haugan, falling timber struck the Savenac Historic Tree Nursery and Visitor Center, causing significant roof damage. In Huson, an uprooted tree lifted a camper and twisted it entirely off its jacks. Meanwhile, at Quinn's Hot Springs south of Paradise, an estimated 75 large trees were toppled by the winds, compounding the massive cleanup efforts required across the region.

At 0940 MST, the Lincoln County Sheriff’s Office issued an Emergency Travel Only order as downed trees and power lines rendered major routes including US-2 and MT-56 impassable. In Libby, a failure of the cellular network created a communications gap for emergency services during the peak of the event.

Property damage was widespread; numerous homes and structures were struck by falling timber, including a home 4 miles NW of Troy and a garage up Pipe Creek. Private losses were notable, including multiple totaled greenhouses and several vehicles crushed by falling Ponderosa pines, such as a late-model truck near the Libby airport and another at Bull Lake. Utility infrastructure was hit hard; numerous downed poles resulted in a total system outage for Lincoln Electric, while Northern Lights and Flathead Electric reported extensive damage to lines, with some Libby-area customers remaining without power for nearly a week. Blacktail Mountain Ski Area was forced to suspend lift operations due to storm-related complications with lift lines.|Due to mild temperatures and additional precipitation, the Yaak River nearly reached minor flood stage on December 17.

Extreme winds battered the higher elevations, with a weather station atop Mount Sentinel (5,026 feet) serving as a proxy for the surrounding peaks. This station recorded a sustained wind of 76 mph and a staggering peak gust of 99 mph from the west-northwest at 0900MST, with gusts consistently exceeding 70 to 90 mph throughout the morning and into the afternoon. Along Highway 12 between Lolo and Lolo Pass, the Montana Department of Transportation warned motorists to limit travel as strong winds blew trees, debris, and rocks onto the roadway around 0820MST west of milepost 32.6. Widespread power outages were reported throughout the area, including significant disruptions up Petty Creek noted by emergency services on the evening of December 17.

Recreational areas experienced staggering timber blowdowns, with snowmachine and cross-country trails covered by hundreds of fallen trees. The Bitterroot Cross-Country Ski Club described it as one of the biggest windstorms they had experienced in years. At the Lolo Pass Visitor Center, officials noted extensive damage with trees completely blocking all cross-country trails. At Chief Joseph Pass, the Bitterroot Cross-Country Ski Club reported hundreds of downed trees; crews had to clear over 150 trees on December 18 just to reopen three main skiable trails. The massive cleanup efforts extended for months; the Missoula Snowgoers Snowmobile Association reported removing 62 trees from a single trail near Lolo Hot Springs as late as February 17, 2026. In the Bitterroot National Forest, Lost Horse Road had multiple trees down across the road and sustained damage to campgrounds.

A historic high wind event impacted the Flathead and Mission Valleys on December 17, 2025, as a powerful cold front brought high winds acting on soils super-saturated by a preceding atmospheric river. Peak gusts frequently exceeded 60 mph across the valley floors, including 67 mph at 0855MST at Glacier Park International Airport, 64 mph at 0915MST at Elmo, and 62 mph at 0900MST at the Creston Agrimet station. The Flathead County Sheriff's Office issued a travel advisory at 1000MST due to hazardous conditions and widespread disruptions. Significant transportation impacts included the closure of US-93 near Somers after a semi-truck was blown across the roadway, and multiple lane blockages on MT-35, MT-200, and Big Mountain Road between 0740MST and 1313MST due to fallen trees and power lines.

Utility infrastructure sustained damage that Flathead Electric Cooperative described as unprecedented and one of the most challenging in their 88-year history. At the 1200MST peak, over 30,000 meters were without power. The combination of high winds and unstable root structures sent trees into lines, causing over 150 individual outages. In Lake County, 5,166 Mission Valley Power customers remained without power as late as 1500MST, with some outages persisting past 1800 MST. These extended outages forced many grocery stores and residents to dispose of all fresh and frozen inventory after being without power for over eight hours.

Property damage was widespread; falling timber caused roof damage to homes in Polson and significant structural damage at the historic Conrad Mansion in Kalispell, where a tree destroyed a gazebo. Public and recreational icons were also affected; the iconic Bigfork cross was destroyed. Flathead County officials described the aftermath as devastating, and final power restoration for the last Flathead Electric members was not completed until 1000MST on December 24.

Peak wind reports across the Missoula and Bitterroot Valleys included 88 mph at the Stevensville Airport at 0956MST, 68 mph at the Little Rock Creek RAWS at 1009MST, 66 mph at the Stevi RAWS at 1014MST, and 61 mph at the Missoula Airport at 0853MST. Hazardous conditions and flying debris severely impacted travel. The Missoula Police Department advised against all unnecessary travel at 0933MST. At 0915MST, fallen trees blocked the left lane of S-203 Southbound, and at 1026MST, US-93 was completely blocked by fallen trees between mile markers 4 and 5. In Missoula, a massive tree fell across West Broadway at Birch Street, pinning a driver inside a vehicle, though they were not injured. Downed trees and power lines also forced the sustained closure of Gharrett Street around 1345MST. In Ravalli County, the Sheriff's Office issued an Emergency Travel Only order as power outages disabled traffic lights and debris blocked numerous roads, including Daly Avenue and Old Corvallis Road.

Falling timber caused catastrophic damage to utility infrastructure. By 1500MST, approximately 30 percent of Ravalli County (7,433 customers) and nearly 7,000 customers in Missoula County were without power. A prominent transmission pole was left leaning precariously over North Reserve Street near Costco in Missoula. Critical services were interrupted; the Ravalli County Airport lost power around 0914MST, and the Hamilton VA Clinic was forced to close completely due to a lack of power and water. Outages were so extensive that they persisted for thousands of customers well into December 19, and final power restoration for Missoula Electric Cooperative members was not completed until 0300MST on December 24.

Structural and property damage was severe. Around 0930MST, intense winds ripped sections of the roof off Jefferson School in Missoula. In Frenchtown, a community pavilion near the elementary school was destroyed. Numerous massive trees crashed into homes and vehicles, including a large pine striking a house between Stevensville and Florence, massive fir trees landing on homes on South Third and Fourth Streets in Hamilton, and a spruce tree crushing two trucks on Pine Street in Stevensville. Schools across the region, including in Frenchtown and Hamilton, were forced to close or issue shelter-in-place holds as conditions deteriorated and phone lines failed.

Extreme wind gusts battered the region, including 76 mph near Avon at 1017MST, 62 mph at the Yankee Flat RAWS at 1040MST, and 58 mph at the Bearmouth MDT at 1132MST. MacDonald Pass on US-12 experienced prolonged severe conditions following a cold front passage at 0847MST, which delivered an initial peak gust of 62 mph, then a maximum sustained wind of 51 mph recorded at 1430MST and gusts peaked at 75 mph at 1700MST. Bert Mooney Airport recorded a peak gust of 67 mph at 1353MST.

Butte-Silver Bow Emergency Management issued a severe weather alert at 0925MST, urging residents to remain indoors, limit travel to emergencies only, and avoid windows due to flying debris, downed trees, and live power lines. By 1330MST, reports indicated high winds left trees either sheared mid-trunk or completely toppled throughout the Butte area. The top half of a massive fir tree snapped on Quartz Street in Uptown Butte, and a spruce tree planted in the 1930s crushed and totaled a parked car in the same neighborhood. The storm compromised the power grid with live downed lines triggering several small ground fires. The destruction was so severe that a representative from the Montana Standard described it as the worst wind damage they had ever witnessed. Law enforcement maintained an emergency-only travel advisory as crews worked throughout the day to clear streets of fallen trees and debris. Also a downed power substation was reported in the Helmville area.

Peak wind gusts included 60 mph at 0846MST at the Bonner I-90 weather station near milepost 110.3. Hazardous conditions and falling timber severely impacted travel corridors throughout the region. East of Hellgate Canyon, a fallen tree partially blocked the westbound off-ramp of I-90 at milepost 107.0 at 1126MST. Highway 200 was closed east of Bonner for a couple of hours due to trees down across both lanes. Along Highway 83, the Montana Department of Transportation issued an obstruction warning for falling trees from milepost 12.0 to 51.0 at 0920MST. Specific blockages on MT-83 included a downed tree causing a partial southbound blockage at milepost 38.5 at 0850MST, and a complete lane blockage at milepost 19.0 near Seeley Lake at 1330MST due to trees and power lines down. The Missoula County Sheriff's Office issued an alert at 1426MST noting traffic delays in both directions from the 19-mile marker. In Clinton, trees were reported down on the roadway at Wallace Creek Road around 1200MST.|Utility infrastructure sustained massive damage. Around 1200MST, power was reported out on Wallace Creek Road in Clinton. By 1800MST on December 17, emergency services reported that a substation was down in the Helmville area, and utility crews were responding to outages in Condon, Placid Lake, and Double Arrow. Thousands of customers remained without power, with the last customer gaining power by 0300MST December 24.

Glacier National Park reported that at least 50 trees fell down along the Going-To-The-Sun Road, Camas Road and bike paths. Multiple trees were reported down 10 miles northwest of Essex, laying against power lines and several had blocked U.S. Highway 2 at Milepost 171. Trees were also blown down on Big Mountain Road leading up to the ski resort. Flathead Electrical COOP reported that over 30,000 members were without power by mid-day of the 17th. They restored most of the power by Christmas Eve.