{{Short description|Recreation area in Fremont County, Wyoming}} {{Use American English|date=July 2025}} {{Use mdy dates|date=August 2023}} {{Infobox park | name = Boysen State Park | image = Boysen State Park (4477236246).jpg | image_size = 280 | image_alt = Picnic area beneath mountains | image_caption = | map = Wyoming | map_caption = Location in Wyoming | map_size = 280 | relief = 1 | map_label = Boysen State Park | location = Fremont County, Wyoming, United States | coordinates = {{coord|43|19|8|N|108|11|2|W|display=inline,title}} | coords_ref = <ref name=gnis/> | area = {{convert|35952|acre|abbr=on}}<ref name=soar2021/> | elevation = {{convert|4728|ft|m|abbr=on}}<ref name=gnis>{{cite gnis|1585867|Boysen Reservoir}}</ref> | established = 1956 | free_label = Named for | free_data = Asmus Boysen | designation = Wyoming state park | administrator = Wyoming State Parks, Historic Sites & Trails | status = | website = {{Official website}} | module = }}

'''Boysen State Park''' is a public recreation area surrounding the Boysen Reservoir, an impoundment of the north-flowing Wind River, in Fremont County, Wyoming. The state park covers more than {{convert|35000|acre}} at the south end of the Owl Creek Mountains at the mouth of the Wind River Canyon.<ref name=park/>

==History== The park was established in 1956 following completion of the Boysen Dam in 1951. It is named for Asmus Boysen, who built the site's first dam in 1908. Part of the original dam can still be seen.<ref name=park/>

==Climate==

According to the Köppen Climate Classification system, Boysen Dam has a cold semi-arid climate, abbreviated "BSk" on climate maps. The hottest temperature recorded at Boysen Dam was {{convert|108|°F}} on July 4, 1954, while the coldest temperature recorded was {{convert|-39|°F}} on January 31, 1979.<ref name=NOWData />

{{Weather box |location = Boysen Dam, Wyoming, 1991–2020 normals, extremes 1948–present |single line = Yes |collapsed = Yes

|Jan record high F = 70 |Feb record high F = 69 |Mar record high F = 77 |Apr record high F = 88 |May record high F = 97 |Jun record high F = 103 |Jul record high F = 108 |Aug record high F = 104 |Sep record high F = 100 |Oct record high F = 89 |Nov record high F = 71 |Dec record high F = 65

|Jan avg record high F = 48.9 |Feb avg record high F = 55.5 |Mar avg record high F = 67.8 |Apr avg record high F = 77.9 |May avg record high F = 86.2 |Jun avg record high F = 94.3 |Jul avg record high F = 100.1 |Aug avg record high F = 97.8 |Sep avg record high F = 92.4 |Oct avg record high F = 80.3 |Nov avg record high F = 63.6 |Dec avg record high F = 52.0 |year avg record high F = 100.4

|Jan high F = 29.7 |Feb high F = 37.2 |Mar high F = 50.4 |Apr high F = 58.7 |May high F = 68.7 |Jun high F = 80.8 |Jul high F = 90.5 |Aug high F = 88.5 |Sep high F = 76.5 |Oct high F = 60.4 |Nov high F = 44.4 |Dec high F = 31.3 |year high F =

|Jan mean F = 17.5 |Feb mean F = 24.0 |Mar mean F = 36.8 |Apr mean F = 45.7 |May mean F = 55.7 |Jun mean F = 66.3 |Jul mean F = 75.1 |Aug mean F = 73.0 |Sep mean F = 61.8 |Oct mean F = 47.5 |Nov mean F = 33.2 |Dec mean F = 20.1 |year mean F =

|Jan low F = 5.4 |Feb low F = 10.7 |Mar low F = 23.3 |Apr low F = 32.7 |May low F = 42.7 |Jun low F = 51.8 |Jul low F = 59.7 |Aug low F = 57.4 |Sep low F = 47.1 |Oct low F = 34.5 |Nov low F = 22.1 |Dec low F = 8.9 |year low F =

|Jan avg record low F = -11.7 |Feb avg record low F = -8.1 |Mar avg record low F = -5.3 |Apr avg record low F = 19.2 |May avg record low F = 30.2 |Jun avg record low F = 40.7 |Jul avg record low F = 51.2 |Aug avg record low F = 48.0 |Sep avg record low F = 35.3 |Oct avg record low F = 20.4 |Nov avg record low F = 6.6 |Dec avg record low F = -8.1 |year avg record low F = -16.4

|Jan record low F = -39 |Feb record low F = -36 |Mar record low F = -21 |Apr record low F = 2 |May record low F = 20 |Jun record low F = 27 |Jul record low F = 41 |Aug record low F = 38 |Sep record low F = 16 |Oct record low F = -3 |Nov record low F = -15 |Dec record low F = -36

|precipitation colour = green |Jan precipitation inch = 0.22 |Feb precipitation inch = 0.32 |Mar precipitation inch = 0.57 |Apr precipitation inch = 1.10 |May precipitation inch = 2.08 |Jun precipitation inch = 1.01 |Jul precipitation inch = 0.75 |Aug precipitation inch = 0.46 |Sep precipitation inch = 0.96 |Oct precipitation inch = 0.90 |Nov precipitation inch = 0.28 |Dec precipitation inch = 0.37 |year precipitation inch =

|Jan snow inch = 2.8 |Feb snow inch = 3.2 |Mar snow inch = 3.8 |Apr snow inch = 1.3 |May snow inch = 0.1 |Jun snow inch = 0.0 |Jul snow inch = 0.0 |Aug snow inch = 0.0 |Sep snow inch = 0.1 |Oct snow inch = 0.8 |Nov snow inch = 1.8 |Dec snow inch = 2.2 |year snow inch =

|unit precipitation days = 0.01 in |Jan precipitation days = 2.9 |Feb precipitation days = 3.5 |Mar precipitation days = 4.1 |Apr precipitation days = 5.9 |May precipitation days = 8.1 |Jun precipitation days = 5.9 |Jul precipitation days = 5.0 |Aug precipitation days = 4.1 |Sep precipitation days = 4.8 |Oct precipitation days = 4.3 |Nov precipitation days = 3.3 |Dec precipitation days = 3.7

|unit snow days = 0.1 in |Jan snow days = 1.8 |Feb snow days = 2.1 |Mar snow days = 2.0 |Apr snow days = 0.9 |May snow days = 0.1 |Jun snow days = 0.0 |Jul snow days = 0.0 |Aug snow days = 0.0 |Sep snow days = 0.1 |Oct snow days = 0.8 |Nov snow days = 1.3 |Dec snow days = 2.0

|source 1 = NOAA<ref name=NOAA> {{cite web |url = https://www.ncei.noaa.gov/access/services/data/v1?dataset=normals-monthly-1991-2020&stations=USC00481000&format=pdf&dataTypes=MLY-TMAX-NORMAL,MLY-TMIN-NORMAL,MLY-TAVG-NORMAL,MLY-PRCP-NORMAL,MLY-SNOW-NORMAL |publisher = National Oceanic and Atmospheric Administration |title = U.S. Climate Normals Quick Access |access-date = August 17, 2022 }} </ref> |source 2 = National Weather Service<ref name = NOWData> {{cite web |url = https://www.weather.gov/wrh/climate?wfo=riw |publisher = National Weather Service |title = NOAA Online Weather Data |access-date = August 17, 2022 }} </ref> }}

==Activities and amenities== The park offers multiple campgrounds, boat launches, and a privately operated marina. Game fish found in the reservoir include walleye, sauger, perch, crappie, ling, rainbow, cutthroat, and brown trout.<ref name=park/>

==References== <references>

<ref name=park>{{cite web |url=https://wyoparks.wyo.gov/index.php/places-to-go/boysen |title=Boysen State Park |work=Wyoming State Parks, Historic Sites & Trails |publisher=State of Wyoming |accessdate=January 22, 2023}}</ref>

<ref name=soar2021>{{cite web |url=https://wyoparks.state.wy.us/pdf/Planning/Soar2021.pdf |title=Table 1. Facilities managed by Wyoming State Parks, Historic Sites and Trails |work=SOAR 2021 |publisher=Wyoming Department of State Parks and Cultural Resources |page=12 |accessdate=March 15, 2017}}</ref>

</references>

==External links== {{stack|{{commons category|Boysen State Park|<br>Boysen State Park}}}} *[https://wyoparks.wyo.gov/index.php/places-to-go/boysen Boysen State Park] Wyoming State Parks, Historic Sites & Trails *[https://wyoparks.wyo.gov/index.php/files/310/Boysen/8/Boysen-Map.pdf Boysen State Park Map] Wyoming Division of State Parks and Historic Sites

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Category:State parks of Wyoming Category:Protected areas of Fremont County, Wyoming Category:Protected areas established in 1956 Category:1956 establishments in Wyoming