Montana, 1997

Flooding in Montana, May 1 to 31, 1997

May 1 to 31, 1997 · NWS MSO · 6 events in 6 counties and zones

Snowmelt flooding caused numerous road closures and road washouts throughout the region. In Flathead County, at least three road washouts were reported and one bridge damaged.

Where it happened

Every event with a place to put it; 6 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
  • Other

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The toll

Deaths
0
Injuries
0
Property damage
$2.3 million
Crop damage
None recorded
Events
6

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS MSO wrote it up.

Snowmelt flooding caused numerous road closures and road washouts throughout the region. In Flathead County, at least three road washouts were reported and one bridge damaged. At least 50 homes were flooded, mainly along Ashley Creek and the Stillwater, Swan and Whitefish Rivers. 50 people were isolated along Truman Creek, which washed out an access road. In Missoula County, at least four bridges were damaged, including a collapsed bridge on Sun Ray Lane in Lolo. Hardest hit was property along the Clark Fork River, Lolo and Rock Creeks. Several culverts and dikes were damaged. In Sanders County, extensive flooding occurred from Plains to Thompson Falls. One road washout resulted in 10 homes being isolated west of Plains along Eddy Creek. At least two bridges were damaged in the county, while four homes were flooded along the Clark Fork River near Plains. In Lake County, five structures were damaged from ground and spring water resulting from snowmelt near Woods Bay. Route 35 near Woods Bay was closed since late April, with 60 acres of flooding. The Jocko River flooded two homes and three trailers, and damaged one bridge. The Swan River flooded one home while the Little Bitterroot River flooded and damaged two bridges. In Ravalli County, six bridges were damaged from snowmelt flooding on the Bitterroot River, with bridges also damaged over Sleeping Child and Skalkaho Creeks. One home lost its foundation and several had water in basements along the Bitterroot River. In Mineral County, snowmelt flooding caused four-25 foot sections of guard rail from Interstate 90 to hang into the Clark Fork River. A 60-foot section of frontage road along the interstate was washed away seven miles east of Superior. In Lincoln County, flooding caused about 15 homes and many roads, culverts and dikes to be flooded along the Yaak River, while one bridge was damaged on O'Brien Creek.

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

6 flood. Local standard time, as filed.

Flood, Kootenai/Cabinet Region

When
May 1, 12:01 AM MST to May 31, 11:59 PM MST
Where
Kootenai/Cabinet Region forecast zone
Property damage
$543,000
Coordinates
48.171, -114.863 (the zone’s center; the record gives no point)

Flood, West Glacier/Bob Marshall Region

When
May 1, 12:01 AM MST to May 31, 11:59 PM MST
Where
West Glacier/Bob Marshall Region forecast zone
Coordinates
47.971, -114.069 (the zone’s center; the record gives no point)

Flood, Flathead/Mission Valleys

When
May 1, 12:01 AM MST to May 31, 11:59 PM MST
Where
Flathead/Mission Valleys forecast zone
Property damage
$912,000
Coordinates
47.872, -114.424 (the zone’s center; the record gives no point)

Flood, Lower Clark Fork/Bitterroot Mountains

When
May 1, 12:01 AM MST to May 31, 11:59 PM MST
Where
Lower Clark Fork/Bitterroot Mountains forecast zone
Coordinates
47.286, -114.685 (the zone’s center; the record gives no point)

Flood, Missoula/Bitterroot Valleys

When
May 1, 12:01 AM MST to May 31, 11:59 PM MST
Where
Missoula/Bitterroot Valleys forecast zone
Property damage
$726,000
Coordinates
46.560, -114.023 (the zone’s center; the record gives no point)

Flood, Upper Clark Fork Valley

When
May 1, 12:01 AM MST to May 31, 11:59 PM MST
Where
Upper Clark Fork Valley forecast zone
Property damage
$69,000
Coordinates
46.306, -113.025 (the zone’s center; the record gives no point)

What these are

Flood
Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Montana in 1997Every state in 1997This day in weather historyWarnings in Montana, May 1997

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 5600147, 5600148, 5600149, 5600150, 5600151, 5600152.