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Grizzly Bear Creek near Keystone

Highest listed crest 6.32 ftFlood stage 4.5 ft27 crests since 1998

The Grizzly Bear Creek near Keystone crested at major flood stage 1 time among the 27 crests the National Weather Service lists from 1998 to 2024. The highest, 6.32 ft on October 11, 2013, was major flooding, 1.82 feet above flood stage.

The gauge

Highest listed crest
6.32 ft
October 11, 2013; 962 cubic feet per second
Flood stage
4.5 ft
Major flooding from 6.0 ft
Crests at major
1
62nd of 155 gauges in South Dakota
Most recent flood crest
May 28, 2019
5.71 ft, moderate flooding
Location
Pennington County
South Dakota
Identifiers
NWS GNKS2
USGS 06403850; out of service

Flood stages

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

Flood categories, Grizzly Bear Creek near Keystone
Action stage4.02Aug 11, 2013The level at which the NWS or its partners begin to take action
Flood stage (minor)4.55Jul 18, 2018Minimal or no property damage, but possibly some public threat
Moderate flood stage5.54May 28, 2019Some inundation of structures and roads near the stream
Major flood stage6.01Oct 11, 2013Extensive inundation of structures and roads

Every listed crest

27 crests from 1998 to 2024. Filled: at or above flood stage. Hover a crest for its date and stage.

Listed crests at the Grizzly Bear Creek near Keystone, 1998 to 2024 02468ft Flood stage 4.5 ftMajor 6.0 ft Jun 18, 1998: 5.12 ft, minor flooding; 423 cubic feet per secondApr 24, 2000: 3.74 ft, below flood stage; 51 cubic feet per secondJul 11, 2001: 5.60 ft, moderate flooding; 713 cubic feet per secondJun 17, 2002: 2.54 ft, below flood stage; 1 cubic feet per secondJun 9, 2003: 2.59 ft, below flood stage; 1 cubic feet per secondMay 23, 2004: 2.89 ft, below flood stage; 5 cubic feet per secondApr 1, 2005: 3.47 ft, below flood stage; 32 cubic feet per secondJun 10, 2006: 4.38 ft, action stage; 174 cubic feet per secondMay 5, 2007: 3.58 ft, below flood stage; 41 cubic feet per secondMay 24, 2008: 5.27 ft, minor flooding; 309 cubic feet per secondJun 14, 2009: 3.72 ft, below flood stage; 47 cubic feet per secondMay 24, 2010: 5.20 ft, minor flooding; 222 cubic feet per secondMay 20, 2011: 5.28 ft, minor flooding; 209 cubic feet per secondJul 21, 2012: 3.34 ft, below flood stage; 13 cubic feet per secondAug 11, 2013: 4.28 ft, action stage; 72 cubic feet per secondOct 11, 2013: 6.32 ft, major flooding; 962 cubic feet per secondMay 24, 2015: 5.68 ft, moderate flooding; 396 cubic feet per secondMay 1, 2016: 1.61 ft, below flood stage; 57 cubic feet per secondMay 20, 2016: 5.78 ft, moderate flooding; 459 cubic feet per secondJun 5, 2017: 3.69 ft, below flood stage; 30 cubic feet per secondJul 18, 2018: 5.42 ft, minor flooding; 346 cubic feet per secondMay 28, 2019: 5.71 ft, moderate flooding; 531 cubic feet per secondJul 5, 2020: 3.13 ft, below flood stage; 20 cubic feet per secondMay 23, 2021: 3.53 ft, below flood stage; 39 cubic feet per secondJun 7, 2022: 2.93 ft, below flood stage; 11 cubic feet per secondMay 14, 2023: 3.33 ft, below flood stage; 28 cubic feet per secondApr 7, 2024: 3.89 ft, below flood stage; 56 cubic feet per second Highest, 6.32 ft, Oct 11, 2013 200020052010201520202025

Crests at or above flood stage, by decade

Crests at or above flood stage per decade, Grizzly Bear Creek near Keystone 1990s: 1 2000s: 2 2010s: 7 7 2020s: 0 1990s2000s2010s2020s
  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, Grizzly Bear Creek near Keystone
1Oct 11, 20136.32+1.82Major962
2May 20, 20165.78+1.28Moderate459
3May 28, 20195.71+1.21Moderate531
4May 24, 20155.68+1.18Moderate396
5Jul 11, 20015.60+1.10Moderate713
6Jul 18, 20185.42+0.92Minor346
7May 20, 20115.28+0.78Minor209
8May 24, 20085.27+0.77Minor309
9May 24, 20105.20+0.70Minor222
10Jun 18, 19985.12+0.62Minor423
11Jun 10, 20064.38−0.12Action174
12Aug 11, 20134.28−0.22Action72
13Apr 7, 20243.89−0.61Below flood stage56
14Apr 24, 20003.74−0.76Below flood stage51
15Jun 14, 20093.72−0.78Below flood stage47
16Jun 5, 20173.69−0.81Below flood stage30
17May 5, 20073.58−0.92Below flood stage41
18May 23, 20213.53−0.97Below flood stage39
19Apr 1, 20053.47−1.03Below flood stage32
20Jul 21, 20123.34−1.16Below flood stage13
21May 14, 20233.33−1.17Below flood stage28
22Jul 5, 20203.13−1.37Below flood stage20
23Jun 7, 20222.93−1.57Below flood stage11
24May 23, 20042.89−1.61Below flood stage5
25Jun 9, 20032.59−1.91Below flood stage1
26Jun 17, 20022.54−1.96Below flood stage1
27May 1, 20161.61−2.89Below flood stage57

Other gauges in Pennington County

Flood gauges in Pennington County
Keystone6.514.50 ft, Jun 9, 19721
Keystone8.014.50 ft, Jun 9, 19721
Rapid City33.534.24 ft, Jul 5, 20190
Deerfield6.06.54 ft, Mar 15, 20190
Scenic18.019.31 ft, Mar 11, 20110
Wasta13.018.00 ft, May 15, 19202
Johnson Siding4.54.88 ft, Jun 24, 20150
Victoria Creek near Rapid City7.513.00 ft, Jun 9, 19721
Water Reclamation Facility near Rapid City9.011.23 ft, May 28, 20190
Big Bend7.07.43 ft, Jun 24, 20150
Founders Park11.011.18 ft, Jun 2, 19970
Hawthorne Ditch at Rapid City16.024.30 ft, Jun 9, 19720
Farmingdale11.012.69 ft, May 24, 20103
Hill City6.06.32 ft, May 26, 20150
Rockerville7.014.00 ft, Jun 10, 19721
Hill City6.58.23 ft, Jun 18, 19981
Victoria Dam nr Rapid City6.58.20 ft, May 28, 20191

Pennington County: every hazard · River floods across the country · South Dakota

NOAA National Water Prediction Service, gauge GNKS2, 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.