Marathon County Severe Weather Facts (1950-2023)
Updated: 01/01/24: Next Update: January 2025
Storm Reports by Decade
Since 1950 there have been 535 documented reports of large hail, damaging winds and
tornadoes across Marathon County. I did include a report from 1921 in this document
which is the state record hail stone of 5.7 inches was set on May 22, 1921. The
population boom of the 1980s and 1990s combined with the SKYWARN program led
to an increase in the number of reports of severe weather during both decades. The
number of reports increased 7% from the 2014-2023 period compared to the 1990s.
One can’t say for sure there has been an increase in severe weather across northeast
Wisconsin. One possible reason for the apparent increase in reports is that in some
instances, multiple reports were received from a single location for the same storm due
to more spotters today. Another reason for the increase in storm reports has been the
focus by the National Weather Service (NWS) to improve warning verification. 2002
was the most active year with thirty-three reports followed by twenty-six reports in
1998, twenty-four reports in 2012 and 2021, nineteen reports in 2006, eighteen reports
in 1997 and 2005, and seventeen reports in 2010. The last time no severe weather was
reported during the year was in 1967. In 2023, there were 14 reports of large hail and
one strong wind/wind damage report.
Days of Severe Weather by Decade
In-order to address the impact of multiple reports for the same storm, the data was
examined by the number of severe weather days. Since the reports were sporadic during
the 1950s through the 1970s, only data from 1980 to present was used. There has been
a 11% increase in the number of days of severe weather from the 2014-2023 period
compared to the 1990s. This trend can be attributed to the increase in population,
technology advances in reporting severe weather, and greater severe weather awareness
by the public. Since 2010, Marathon County averages 5.1 days of severe weather per
year. The long-term average from 1980-2023 is 4.8 days. The most active year was
2002 with ten days of severe weather; followed by nine days of severe weather in 1998
and 2021, eight days in 1999, and seven days in 1984, 2004, 2006, 2011, 2016 and
2018. In 2023, there were five days of severe weather: May 6, July 27, July 28, August
11 and October 24. An unusually large hail was reported across portions of central and
northeast Wisconsin on October 24
th
.
4
15
40
46
110
140
126
54
0
20
40
60
80
100
120
140
160
50s 60s 70s 80s 90s 00s 10s 20s
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s
Storm Reports by Decade
4
14
28
34
46
58
51
23
0
10
20
30
40
50
60
70
50s 60s 70s 80s 90s 00s 10s 20s
D
a
y
s
Days of Severe Weather
2
1 1
5
7
2
3
6
4
3 3 3
5
1
2
5
4
6
9
8
4
6
10
3
7
6
7
6
5
4
5
7
6
3
2
3
7
5
7
6
5
9
4
5
0
2
4
6
8
10
12
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
D
a
y
s
Number of Days of Severe Weather Since 1980
Marathon County Severe Weather Facts (1950-2023)
Storm Reports by Month
Severe weather has been recorded in Marathon County from March through November. A rare event can occasionally occur in
March. The earliest documented report of severe weather during the year occurred on March 8, 2000 when one inch hail was
reported at Stratford. The severe weather season begins in earnest in April. The heart of the convective season is May through July
and accounts for 67% of all severe weather reports. July is the peak month for severe weather. Severe weather reports quickly
wanes by September. The warm season months from May through September accounted for 88% of all severe weather reports
during the year. Severe weather can occur from time to time in September with isolated reports during October and November. In
2023, two-inch diameter hail was report a mile and a half north-northwest of Mosinee while 1.75 inch hail was reported nearly a
mile south of Knowlton on October 24
th
between 9 am and 10 am. Marathon County is the only county in the Green Bay forecast
area that has recorded a tornado during November. A tornado was reported from Chili in Clark County to Rib Mountain on
November 15, 1960. Until 2021, the latest report of severe weather during the year in Marathon County occurred on November
21, 1990, when wind damage was reported three miles north of Nutterville or eight miles northeast of Wausau. In 2021, unusually
mild temperatures help trigger severe thunderstorms across Iowa and southeast Minnesota into Wisconsin on December 15
th
. A
weakening line of severe thunderstorms brought strong winds and wind damage to near Colby around 9:37 PM CST and about
two miles north-northwest of Marathon around 10:10 PM CST.
NOTE: The chart depicts storm type by month: (hail, wind/wind damage, tornadoes).
0 0
2
39
92
121
154
64
41
17
3
2
0
20
40
60
80
100
120
140
160
180
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
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All Storm Reports by Month
0 0
1
24
50
42
40
21
6
13
0 00 0
1
10
36
64
98
37
27
4
2 2
0 0 0
5
6
15
16
6
8
0
1
0
0
20
40
60
80
100
120
JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
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Storm Reports By Month
Hail Wind Tornadoes
Marathon County Severe Weather Facts (1950-2023)
Storm Reports by Time of Day
No matter the season, the afternoon and early evening hours are the peak time for severe weather across Marathon County. Overall,
62% of all severe weather reports occur between 1 PM and 9 PM CST. In Marathon County, severe weather reports increased
sharply after 1 PM CST with a peak between 3 PM and 7 PM CST. The peak in the storm activity corresponded to the afternoon
heating when the atmosphere is most unstable. During May through September, there was another minor peak in activity between
midnight and 6 AM CST. In these events, severe thunderstorms develop across Minnesota and the Dakotas which move into the
county overnight. Although rare to see severe weather between 6 AM and NOON CST, Marathon County had the highest number
of reports during this time frame in the Green Bay forecast area. In 2012, there was a rare outbreak of severe weather between
6:50 AM and 8:05 AM CST on October 25
th
. This line of thunderstorms produced hail up to 1.25 inches and produced widespread
wind damage across the western half of the county.
15
11
6
7
10
5
7
5
6
10
12
15
22
14
24
43
48
61
64
42
38
28
17
25
0
10
20
30
40
50
60
70
12A 1A 2A 3A 4A 5A 6A 7A 8A 9A 10A 11A 12P 1P 2P 3P 4P 5P 6P 7P 8P 9P 10P 11P
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s
Severe Weather Reports By Hour (CST)
Marathon County Severe Weather Facts (1950-2023)
Severe Weather Reports Midnight to 6 AM CST
Overnight severe weather reports are most prominent during the summer (June through August) due to nocturnal convection along
warm fronts, or from complexes of storms that develop across the Dakotas and Minnesota and roll through northeast Wisconsin
during the early morning hours. The summer months account for 65% of all overnight reports of severe weather during the year.
0
12
35
7
0
10
20
30
40
WINTER (DEC-FEB) SPRING (MAR-MAY) SUMMER (JUN - AUG) FALL (SEP-NOV)
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Midnight to 6 AM CST Reports By Season
Marathon County Severe Weather Facts (1950-2023)
All Marathon County Tornadoes
Event
Date
Time
F/EF
#
Month
Day
Year
(CST)
Start / End Location
Rank
1
6
25
1950
21:10
2 W Unity - 3 NE Abbotsford
2
2
6
20
1954
02:30
Mosinee
2
3
6
4
1958
19:30
6 SE Chippewa Falls to 2 NW Athens
3
4
5
4
1959
10:30
Wausau
1
5
11
15
1960
14:25
Chili to near Rib Mountain
2
6
9
3
1961
00:10
Fenwood
2
7
9
3
1961
01:00
Athens
1
8
5
8
1964
17:50
7 ESE Knowlton - 5 W Elderon
2
9
8
19
1968
17:30
4 W Fenwood - 11 E Fenwood
2
10
9
28
1971
14:15-16:05
3 NE Brokaw - 6 NE Hogarty
3
11
9
28
1971
16:00
1 NE Abbotsford - Athens
3
12
6
18
1973
11:00
2 W Athens
1
13
4
12
1974
14:05
5 W Athens
2
14
6
13
1976
20:00
2 W Hogarty - Elton
1
15
8
31
1977
18:15
Rib Mountain - Wausau
3
16
7
15
1982
19:15
Mayflower Lake
1
17
7
3
1983
17:35
6 W Unity - Cherokee
2
18
6
26
1984
16;55
13 N Wausau - Texas
1
19
9
24
1984
16:50
13.5 WSW Wausau - Wausau
2
20
7
2
1987
17:10
Pike Lake
1
21
5
8
1988
17:10
4.5 SW Hadler - Rib Falls
2
22
9
19
1988
16:37
1 W Edgar
0
23
6
12
1990
18:35
2 W Stratford
1
24
7
19
1992
15:54
2 WSW Stratford
1
25
7
8
1994
14:00
3 NW Elderon
1
26
8
7
1996
01:45-01:49
6.5 N Stratford - 2.5 NNW Fernwood
2
27
8
7
1996
01:46-01:47
1 N - 1.2 NE Stratford
1
28
8
7
1996
02:19-02:21
4 SW Shantytown - Shantytown
1
29
7
16
1997
14:40-14:45
8.5 NNE - 6.9 NE Nutterville
2
30
7
16
1997
15:00-15:02
4 SW - 4.2 SW Hogarty
0
31
7
16
1997
15:00-15:01
3 N Sunset
0
32
7
16
1997
15:09-15:11
2 NE - 1.8 NE Ringle
1
33
7
16
1997
15:20-15::22
2 N - 1.8 N Elderon
0
34
5
31
1998
00:20-00:21
4 WSW Mosinee
0
35
4
18
2002
18:13-18:27
3 SE Stratford - 6 NW Mosinee
1
36
4
18
2002
18:32
6 SSW Wausau Airport
0
37
7
30
2002
1822-1828
3 W - 0.8 W Central Wisconsin Airport
0
38
9
2
2002
1704-1706
5.2 W - 5 W Athens
0
39
9
2
2002
1735-1743
6 NW Wausau - 4 NE Wausau
1
40
6
4
2005
1527-1529
4 W - 4.5 WNW Edgar
0
Marathon County Severe Weather Facts (1950-2022)
All Marathon County Tornadoes Continued
Event
Date
Time
F/EF
#
Month
Day
Year
(CST)
Start / End Location
Rank
41
6
4
2005
15:39-15:42
1 W - 1.5 NW Athens
0
42
6
4
2005
17:06
4 S Athens
0
43
6
4
2005
17:20
3 W Marathon
0
44
6
4
2005
19:18
7 S Hogarty
0
45
6
10
2005
13:03
4 W Mosinee
0
46
6
7
2007
15:01-15:14
1.4 W Peplin - 0.9 N Pike Lake
2
47
5
25
2008
20:00-20:01
3 ENE Knowlton
0
48
7
29
2008
15:27
3.6 NW Granite Heights
0
49
7
29
2008
15:59-16:00
6.3 NNW Kalinke
0
50
4
10
2011
17:08-17:41
2 N Hamburg - 1 SW Bloomfield
0
51
5
24
2012
18:01-18:07
3.7 SSE - 4.8 ENE Marathon
0
52
6
30
2016
18:16
0.8 WSW Poniatowski
0
53
8
4
2016
10:20-10:26
1.3 NNE Cherokee - 4.4 SSW Stratford
1
54
4
9
2017
23:54-23:55
5.0 SSW Taegsville - 4.9 S Taegsville
1
55
7
19
2019
19:20-19:30
1.5 SSW Moon - 3.9 ENE Knowlton
1
56
7
28
2021
19:40-19:44
4.8 SE Merrill - 2.8 NE Granite Heights
1
57
7
28
2021
20:18-20:19
0.4 SSE - 0.6 SSE Peplin
0
Additional tornado data can be found on the NWS Green Bay webpage at: http://www.weather.gov/grb/severeclimate
F/EF2 or Greater Tornadoes in Marathon County
Event
Date
Time
F/EF
#
Month
Day
Year
(CST)
Start / End Location
Rank
1
6
25
1950
21:10
2 W Unity - 3 NE Abbotsford
2
2
6
20
1954
02:30
Mosinee
2
3
6
4
1958
19:30
6 SE Chippewa Falls - 2 NW Athens
3
4
11
15
1960
14:25
Chili to near Rib Mountain
2
5
9
3
1961
00:10
Fenwood
2
6
5
8
1964
17:50
7 ESE Knowlton - 5 W Elderon
2
7
8
19
1968
17:30
4 W Fenwood - 11 E Fenwood
2
8
9
28
1971
14:15-16:05
3 NE Brokaw - 6 NE Hogarty
3
9
9
28
1971
16:00
1 NE Abbotsford - Athens
3
10
4
12
1974
14:05
5 W Athens
2
11
8
31
1977
18:15
Rib Mountain - Wausau
3
12
7
3
1983
17:35
6 W Unity - Cherokee
2
13
9
24
1984
16:50
13.5 WSW Wausau - Wausau
2
14
5
8
1988
17:10
4.5 SW Hadler - Rib Falls
2
15
8
7
1996
01:45-01:49
6.5 N Stratford - 2.5 NNW Fernwood
2
16
7
16
1997
14:40-14:45
8.5 NNE - 6.9 NE Nutterville
2
17
6
7
2007
15:01-15:14
1.4 W Peplin - 0.9 N Pike Lake
2
Marathon County Severe Weather Facts (1950-2023)
Tornadoes
Since record keeping began in 1950, there have been 57 documented
tornadoes in Marathon County. Of the 57 tornadoes, there have been four
documented tornadoes of F/EF3 or greater intensity. There have been four
F/EF3 tornadoes to strike the county. The last F3 tornado occurred on
August 31, 1977. The tornado touched down one mile northeast of
Abbotsford and then moved to near Athens. Thirteen tornadoes were rated
F/EF2, nineteen tornadoes were rated F/EF1, and twenty-one tornadoes
were rated F/EF0. The most active year was 2005 with six tornadoes,
followed by five tornadoes in 1997 and 2002, and three tornadoes in 1996.
A tornado was reported in the county for four consecutive years from 1958
to 1961 and three consecutive years from 1982 to 1984 and 1996 to 1998.
Since 1950, tornadoes have touched down in thirty-four different years. In
2021, an EF1 tornado touched down in Lincoln County and moved into
Marathon County before dissipating nearly three miles northeast of
Granite Heights on July 28th. Another tornado (EF0) occurred on this date
just southeast of Peplin. A tornado strike in Marathon County occurs on
average about every year and a half.
Tornadoes by Month
Documented tornadoes have occurred in Marathon County from April
through September with a rare tornado in November. In 2017,
Marathon County experienced the earliest tornado on record in a
calendar year on April 10
th
when an EF1 tornado touched down about
five miles southwest of Taegsville. The previous earliest documented
tornado during the year occurred on April 12, 1974, when a F2 tornado
touched down five miles west of Athens. The tornado season peaks in
June and July, which account for 54% of all tornado reports. There
were more documented tornadoes in September than in August.
During September, cold fronts are typically stronger while the jet
stream is beginning to shift southward during the fall which may
explain the increase in tornado activity. The warm season months of
May through September account for 89% all tornadoes during the
year. The latest tornado on record during the year occurred on
November 15, 1960 when a F2 tornado touched down near Chili in
Clark County and traveled to near Rib Mountain.
0 0 0
5
6
15
16
6
8
0
1
0
0
2
4
6
8
10
12
14
16
18
JAN
FEB
MAR
APR
MAY
JUN
JUL
AUG
SEP
OCT
NOV
DEC
T
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n
a
d
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s
Tornadoes by Month
21
19
13
4
0 0
F/EF0 F/EF1 F/EF2 F/EF3 F/EF4 F/EF5
0
5
10
15
20
25
T
o
r
n
a
d
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e
s
Number of Tornadoes By F/EF Scale
Marathon County Severe Weather Facts (1950-2023)
Tornadoes by Hour
In Marathon County, 45 documented tornadoes (79%) have occurred between 2 PM and 10 PM CST. There have been zero
documented tornadoes between 3 AM and 9 AM CST.
Predominant Storm Reports – Wind and Hail Only
During April, May and October, large hail is the dominant weather event that is reported to the National Weather Service. Typically
the atmosphere is colder during this time of year to support large hail. For the remainder of the convective season, reports of high
winds or wind damage are more likely to be reported than large hail. Wind events are the most predominant report type during
June through September.
% Hail
% Wind or
% Hail
% Wind or
Month
Reports
Wind Damage
Month
Reports
Wind Damage
Jan
0.0
0.0
Jul
29.0
71.0
Feb
0.0
0.0
Aug
36.2
63.8
Mar
50.0
50.0
Sep
18.2
81.8
Apr
70.6
29.4
Oct
76.5
23.5
May
58.1
41.9
Nov
0.0
100.0
Jun
39.6
60.4
Dec
0.0
0.0
Year
41.2
58.8
2
3
2
0 0 0 0 0 0 0
2
1
0
1
4
10
5
10
7
5
3
1
0
1
0
1
2
3
4
5
6
7
8
9
10
11
12
12A
1A
2A
3A
4A
5A
6A
7A
8A
9A
10A
11A
12P
1P
2P
3P
4P
5P
6P
7P
8P
9P
10P
11P
T
o
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n
a
d
o
e
s
Tornadoes By Hour
Marathon County Severe Weather Facts (1950-2023)
Large Hail in Marathon County
There have only been four documented reports of hail two inches or greater in diameter across the county. The largest hail stone
documented in the county was 5.7 inches in diameter which occurred in Wausau in 1921. This hailstone is also the state record for
Wisconsin. The last hailstone two inches or greater in diameter occurred on October 24, 2023 when 2-inch diameter hail was
reported a mile and a half north-northwest of Mosinee. Overall, hail ranging in size from three quarters to one inch accounted for
79% of the documented large hail reports. Large hail reports of two inches or greater only accounted for 2% of the total hail
reports.
Hail over 2 inches
Date
Time
Hail
Rank
Month
Day
Year
(CST)
Start / End
(Inches)
1
5
22
1921
??
Wausau (state record)
5.70
2
4
25
2008
17:07
Marathon
2.75
3
6
13
2004
06:19
Marathon
2.25
4T
10
24
2023
09:36-09:37
1.5 NNW Mosinee
2.00
4T
7
18
1996
09:15
2 E Brokaw
2.00
Note: The state record hailstone was included in the graph.
88
105
4
0 0
1
< 1 1 - 1.99 2 - 2.99 3 - 3.99 4 - 4.99 5 - 5.99
0
10
20
30
40
50
60
70
80
90
100
110
120
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s
Hail Reports By Size (Inches)
Marathon County Severe Weather Facts (1950-2023)
Marathon County Summary
In Marathon County, the severe weather season begins in earnest in April, peaks in June and July and then wanes quickly by
September. Severe weather usually occurs in the afternoon and early evening hours, with a secondary peak between midnight and
6 AM CST during the summer months. If you do experience severe weather, you are likely to see large hail early in the spring or
late fall. Damaging wind or large hail will be the dominant severe weather report during the remainder of the convective season.
In the Green Bay County Warning Area which includes 22 counties from central to northeast Wisconsin, Marathon County ranks
1
st
in the total number of storm reports and 1
st
in the number of tornado reports since 1950.
Green Bay Forecast Area Severe Weather Climatology Summary
Across the Green Bay forecast area which covers 22 counties in north-central and northeast Wisconsin, severe weather has been
documented in every month except February. This includes a rare event on January 24, 1967, in which a line of thunderstorms
produced damaging winds across Brown, Winnebago, and Outagamie counties during the early evening hours. Another rare late
season thunderstorm produced one inch hail in Florence County on December 5, 2001, while one inch hail was reported four miles
west of St. Nazianz in Manitowoc County on December 20, 1967.
Tornadoes have occurred from March through December, with an extremely rare tornado outbreak occurring on December 1,
1970. On this date four tornadoes were reported across central and northeast Wisconsin during the morning. A strong area of low
pressure brought unseasonably mild temperatures and severe thunderstorms to portions of central and northeast Wisconsin as a
cold front swept across the state. The first tornado was reported twelve miles southeast of Marshfield in Wood County around 7
AM CST while another tornado was reported in the town of Hull in Portage County around 9 AM CST. Later that morning, a F2
tornado was reported in Waupaca and Shawano counties, from four miles southwest of Iola to near Marion and Pella. The last and
strongest tornado occurred around 9:45 AM CST. The F3 tornado travelled from Medina in southwest Outagamie County to far
southeast Shawano County, destroying about 20 barns and five homes.
Here are the strongest documented tornadoes in the Green Bay forecast area which covers 22 counties in central, north-central and
northeast Wisconsin.
F/EF4 Tornadoes
Event
Date
Time
Tor in GRB Service Area
#
Month
Day
Year
(CST)
Start / End Location
County or Counties
1
6
25
1950
21:00
1 W Woodboro - 5 NE Rhinelander
Oneida
2
9
26
1951
15:45-16:08
9 SSW Amherst - 2 SW Bear Creek
Portage-Waupaca
3
4
3
1956
13:45-13:53
Berlin - 2 W Omro
Waushara-Winnebago
4
8
19
1968
16:10
3 SW Pound - Marinette
Marinette
5
4
21
1974
14:40-15:08
5 S Ripon - Oshkosh
Winnebago
6
4
27
1984
15:20-15:40
1 NE Winneconne - Freedom
Winnebago-Outagamie
7
7
5
1994
15:43-15:55
2.5 NW Maribel - 0.5 W Cooperstown
Manitowoc
Marathon County Severe Weather Facts (1950-2023)
Green Bay Forecast Area Severe Weather Climatology Summary
The state record for the largest documented hail stone in Wisconsin occurred in Wausau on May 22, 1921. The hailstone measured
5.7 inches in diameter. More recently, a hailstone of 5.5 inches in diameter was reported in Port Edwards in southeast Wood
County on June 7, 2007. In 2021, there were three reports of hail four inches in diameter or greater across northeast Wisconsin.
Hail
Month
Date
Year
Time (CST)
Start / End Location
County
5.70
5
22
1921
??
Wausau
Marathon
5.50
6
7
2007
15:23
Port Edwards - Wisconsin Rapids
Wood
4.50
9
7
2021
07:47-07:48
2 W Apple Creek
Outagamie
4.50
7
16
1997
14:15
8 NE Merrill
Lincoln
4.25
5
22
2011
15:05
0.8 NW Winchester
Winnebago
4.25
5
22
2011
14:35
0.5 E Redgranite
Waushara
4.10
9
7
2021
07:45-07:46
3 NE Greenville
Outagamie
4.00
9
7
2021
08:13-08:14
2 E Apple Creek
Outagamie
4.00
8
2
2015
13:32
2.8 S Brookside
Oconto
4.00
8
2
2015
13:24
0.5 E Abrams
Oconto
4.00
4
25
2008
17:50
0.8 SW Kings
Lincoln
4.00
7
1
2006
14:31
1 N Hayes - Suring
Oconto
4.00
3
29
1998
12:25
St. John
Calumet
3.75
9
7
2021
07:47-07:48
1 NW Little Chute
Outagamie
3.50
6
8
2000
22:30
10 W Middle Inlet
Marinette
3.25
7
1
2006
15:05
Oconto - 6 SE Oconto Falls
Oconto
3.00
10
24
2023
08:50-08:51
Nasonville
Wood
3.00
8
2
2015
14:06
Rudolph
Wood
3.00
5
22
2011
17:35
Plover
Portage
3.00
6
7
2007
15:50
5 W Langlade
Langlade
3.00
7
1
2006
19:29
Branch - Manitowoc
Manitowoc
3.00
4
18
2002
15:30
7 WSW Bloomville - 7 NW Bradley
Lincoln
3.00
8
9
2001
12:50
1S Sturgeon Bay
Door
3.00
6
5
1999
18:24
3 S - 8 SE Eagle River
Vilas
3.00
7
27
1989
10:50
1 N Oshkosh
Winnebago
3.00
8
19
1968
16:15
2 E Harmony
Marinette
3.00
7
19
1963
15:00
4 S Rhinelander
Oneida
3.00
7
1
1956
11:00
5 E Green Bay
Brown