Atmospheric River Flooding Devastates Libby, Montana and Surrounding Communities as More Rain and Wind Approach

Rivers Rise Across Northwestern Montana

A series of atmospheric rivers pushed into western Montana last week, unleashing heavy rain and accelerating snowmelt across mountain basins. Water poured into creeks and rivers. Channels swelled fast. Infrastructure failed under the pressure.

In northwestern Montana, rapid runoff destroyed bridges and washed out roads as torrents rushed through normally calm waterways. Some locations received close to half a foot of rain over a short period, with melting snow adding to the surge.

Flash flooding took hold in Lincoln County, MT, including the towns of Libby, MT and Troy, MT. Creeks turned violent. Roads disappeared. Water spread into neighborhoods.

Bridges Lost and Roads Washed Away

Officials reported that at least five bridges were destroyed, including structures along Lauer Lane leading toward Swede Mountain. Multiple roads were washed out, cutting off access in several areas.

Video from Farm to Market Road south of Libby, MT captured the moment when a section of roadway collapsed into churning floodwater. The ground gave way. The river claimed the pavement.

Homes in low-lying areas were surrounded by water. The full extent of the damage remains unclear as assessments continue across remote terrain.

State of Emergency Declared

On December 11, Montana Governor Greg Gianforte declared a flooding emergency in northwestern Montana to speed the deployment of resources.

“Continued rainfall across northwestern Montana has flooded some of our communities, including the town of Libby," Gianforte said. “This order will ensure resources are deployed quickly and effectively to protect Montanans and their property."

The declaration came as floodwaters continued to strain infrastructure already weakened by prolonged moisture.

A Night Residents Will Not Forget

Terry Crooks has lived along Granite Creek south of Libby, MT since 1980 and has seen floods before. This one felt different.

“I could hear the river when I went to bed, and I knew it did not sound good," Crooks said.

Hours later, near 1 a.m. on December 12, a Lincoln County sheriff’s deputy knocked on his door.

“Your house is surrounded by water, and it is coming up," Crooks recalled the deputy saying.

Across southern Lincoln County, similar warnings were delivered as heavy rain and melting snow turned quiet creeks into roaring whitewater.

Emergency Response Under Strain

Local officials acknowledged that while flooding had been forecast, the scale of destruction exceeded expectations. Roads were inundated. Neighborhoods flooded. At least half a dozen bridges were damaged or destroyed.

“This flooding event will have significant and long-lasting impacts on the south end of the county," said Lincoln County Sheriff Darren Short during a town hall meeting in Libby, MT. “We still do not know the full extent of the damage."

Boyd White, head of the Lincoln County Emergency Management Agency, said crews worked through exhaustion as water levels kept rising beyond early forecasts.

“It took us by surprise," White said.

Trucks carrying dirt and sandbags were dispatched to Granite Creek, Libby Creek, and Flower Creek as responders raced to protect homes.

Community Effort Along Granite Creek

As water surrounded homes along Farm to Market Road, residents stepped in. After moving his car to higher ground, Crooks began filling sandbags to shield his house and his neighbor’s property.

Church groups arrived. High school students joined in. A berm took shape along Granite Creek Road.

“It is a tragedy," Crooks said, “but the camaraderie really lifts your heart."

Before officials could close Farm to Market Road, one driver went off a damaged bridge. The man escaped unharmed. His vehicle remains in the river.

Damage Spreads Beyond Libby

Officials estimate that seven bridges have been damaged or destroyed so far, with more likely to be discovered along remote roads in the Kootenai National Forest. Deputies continue to patrol and document damage as it appears.

Jeff Gruber, a local historian in Libby, MT, compared the flooding to a major event in 1974.

“All that water came down the hill at once," he said, recalling a flood that followed heavy rain and snowmelt decades earlier.

Levi Thompson, a construction company owner who lives along Libby Creek, said floodwater reached his home. While damage appeared limited, full assessments are still pending. Thompson and his crew have been clearing debris under bridges in Libby, MT and Troy, MT to keep water moving.

Reservoir Concerns and Drinking Water

Attention has also turned to water infrastructure. Officials warned that flooding may have compromised a dike holding back the Lower Flower Creek Reservoir, one of two reservoirs supplying Libby, MT with drinking water.

Residents along Flower Creek were alerted. Monitoring intensified. Officials later said evacuations were not warranted, though risks remain.

“Could there be damage? Yes," White said. “But I do not think we are going to see homes washed away and piled up."

County officials began slowly draining the lower reservoir to reduce pressure on the dike. The process is expected to take three days.

The City of Libby issued a boil water order for all residents, advising water be boiled for at least three minutes before use. Officials said the order will likely remain in place for another week.

More Rain and a Powerful Windstorm Ahead

Recovery efforts are unfolding under an unsettled forecast. Another atmospheric river is expected to arrive from Monday through Wednesday, bringing additional rain and snow.

Forecasters call for 1 to 2 inches of rain in valley locations and 2 to 3 inches in the mountains. Creeks and rivers are expected to rise again, though officials hope totals will remain below last week’s extreme levels.

By midweek, attention shifts to wind. A powerful storm system is forecast to bring gusts up to 70 miles per hour across much of Montana, with gusts approaching 80 miles per hour in higher terrain of northwestern Montana. The AccuWeather Local StormMax stands at 105 miles per hour.

Winds of that strength can down trees, damage structures, and trigger power outages. Travel disruptions are likely, especially for high-profile vehicles.

Snow will persist in higher elevations into late week. Snow levels are forecast to drop through Thursday, briefly reaching some valley floors before rising again.

For now, residents along creeks and rivers continue to watch the water. Sandbags line yards. Berms stand firm. The ground remains saturated, and the storm track remains active.