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Swan River near Bigfork

Highest listed crest 7.34 ftFlood stage 6.5 ft23 crests since 1933

The Swan River near Bigfork crested above flood stage 8 times among the 23 crests the National Weather Service lists from 1933 to 2026. The highest, 7.34 ft on June 20, 1974, was minor flooding, 0.84 feet above flood stage.

The gauge

Highest listed crest
7.34 ft
June 20, 1974; 8,890 cubic feet per second
Flood stage
6.5 ft
Major flooding from 8.0 ft
Crests at major
0
8 above flood stage
Most recent flood crest
June 22, 2022
6.61 ft, minor flooding
Location
Lake County
Montana

Flood stages

The thresholds the National Weather Service uses for this gauge today, and how many listed crests reached each.

Flood categories, Swan River near Bigfork
Action stage6.014May 27, 2021The level at which the NWS or its partners begin to take action
Flood stage (minor)6.58Jun 22, 2022Minimal or no property damage, but possibly some public threat
Moderate flood stage7.50—Some inundation of structures and roads near the stream
Major flood stage8.00—Extensive inundation of structures and roads

Every listed crest

23 crests from 1933 to 2026. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Swan River near Bigfork, 1933 to 2026 5.566.577.58ft Flood stage 6.5 ftMajor 8.0 ft Jun 18, 1933: 7.00 ft, minor flooding; 8,280 cubic feet per secondMay 11, 1947: 6.11 ft, action stage; 5,960 cubic feet per secondMay 24, 1948: 7.12 ft, minor flooding; 8,400 cubic feet per secondJun 23, 1950: 6.01 ft, action stage; 5,900 cubic feet per secondJun 4, 1956: 6.42 ft, action stage; 6,790 cubic feet per secondMay 27, 1958: 6.05 ft, action stage; 5,920 cubic feet per secondJun 22, 1959: 6.72 ft, minor flooding; 7,520 cubic feet per secondMay 29, 1961: 6.38 ft, action stage; 6,810 cubic feet per secondJun 10, 1964: 6.98 ft, minor flooding; 8,100 cubic feet per secondJun 20, 1965: 6.00 ft, action stage; 6,010 cubic feet per secondJun 8, 1970: 6.58 ft, minor flooding; 7,230 cubic feet per secondJun 12, 1972: 6.25 ft, action stage; 6,540 cubic feet per secondJun 20, 1974: 7.34 ft, minor flooding; 8,890 cubic feet per secondJun 1, 1986: 6.15 ft, action stage; 6,340 cubic feet per secondMay 18, 1997: 7.27 ft, minor flooding; 8,520 cubic feet per secondJun 18, 2006: 6.06 ft, action stage; 6,170 cubic feet per secondJul 2, 2011: 6.20 ft, action stage; 6,710 cubic feet per secondMay 15, 2013: 6.08 ft, action stage; 6,210 cubic feet per secondMay 29, 2018: 6.27 ft, action stage; 6,580 cubic feet per secondJun 2, 2020: 6.07 ft, action stage; 6,150 cubic feet per secondMay 27, 2021: 6.19 ft, action stage; 6,400 cubic feet per secondJun 22, 2022: 6.61 ft, minor flooding; 7,290 cubic feet per secondJun 2, 2026: 5.76 ft, below flood stage; 5,520 cubic feet per second Highest, 7.34 ft, Jun 20, 1974 19401960198020002020

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Swan River near Bigfork 1930s: 1 1940s: 1 1950s: 1 1960s: 1 1970s: 2 2 1980s: 0 1990s: 1 2000s: 0 2010s: 0 2020s: 1 1930s1940s1950s1960s1970s1980s1990s2000s2010s2020s
  1. These are the crests the local National Weather Service office lists for the gauge: the highest on record and recent crests. Lesser floods between them may be missing, so counts by decade are a floor.
  2. Categories use today's flood stages. Levees, dams and channel changes since a crest can make old and new stages not directly comparable.

Highest crests

Highest listed crests, Swan River near Bigfork
1Jun 20, 19747.34+0.84Minor8,890
2May 18, 19977.27+0.77Minor8,520
3May 24, 19487.12+0.62Minor8,400
4Jun 18, 19337.00+0.50Minor8,280
5Jun 10, 19646.98+0.48Minor8,100
6Jun 22, 19596.72+0.22Minor7,520
7Jun 22, 20226.61+0.11Minor7,290
8Jun 8, 19706.58+0.08Minor7,230
9Jun 4, 19566.42−0.08Action6,790
10May 29, 19616.38−0.12Action6,810
11May 29, 20186.27−0.23Action6,580
12Jun 12, 19726.25−0.25Action6,540
13Jul 2, 20116.20−0.30Action6,710
14May 27, 20216.19−0.31Action6,400
15Jun 1, 19866.15−0.35Action6,340
16May 11, 19476.11−0.39Action5,960
17May 15, 20136.08−0.42Action6,210
18Jun 2, 20206.07−0.43Action6,150
19Jun 18, 20066.06−0.44Action6,170
20May 27, 19586.05−0.45Action5,920
21Jun 23, 19506.01−0.49Action5,900
22Jun 20, 19656.00−0.50Action6,010
23Jun 2, 20265.76−0.74Below flood stage5,520

Other gauges in Lake County

Flood gauges in Lake County
Polson18.021.00 ft, Jun 1, 18940

Lake County: every hazard · River floods across the country · Montana

NOAA National Water Prediction Service, gauge SWRM8, retrieved October 30, 2026. Stages in feet on the gauge's own datum, not elevation. Crests are as the National Weather Service lists them; preliminary values may be revised.