Editing List of counties in Montana

{{Short description|None}}
{{Use mdy dates|date=April 2024}}
{{Infobox subdivision type
| name               = Counties of Montana
| alt_name           =  
| map                = {{Montana County Labelled Map}}
| category           = 
| territory          = [[State of Montana]]
| start_date         =
| current_number     = 56
| number_date        =
| population_range   = 525 ([[Petroleum County, Montana|Petroleum]]) – 171,583 ([[Yellowstone County, Montana|Yellowstone]])
| area_range         = {{Convert|718|sqmi}} ([[Silver Bow County, Montana|Silver Bow]]) – {{Convert|5543|sqmi}} ([[Beaverhead County, Montana|Beaverhead]])
| government         = [[County government]]
| subdivision        =  cities, towns, unincorporated communities, Indian reservations, [[census designated place]]
}}
This is a '''list of the [[County (United States)|counties]] in the [[U.S. state]] of [[Montana]]'''. There are 56 counties in the state.

Montana has two consolidated city-counties&mdash;[[Anaconda, Montana|Anaconda]] with [[Deer Lodge County, Montana|Deer Lodge County]] and [[Butte, Montana|Butte]] with [[Silver Bow County, Montana|Silver Bow County]].  The portion of [[Yellowstone National Park]] that lies within Montana was not part of any county until 1978, when part of it was nominally added to [[Gallatin County, Montana|Gallatin County]], and the rest of it to [[Park County, Montana|Park County]].

Montana's [[United States postal abbreviations|postal abbreviation]] is '''MT''' and its [[FIPS state code]] is '''30'''.
{{clear}}

==Counties==
The [[Federal Information Processing Standard]] (FIPS) code, which is used by the United States government to uniquely identify counties, is provided for each county. The FIPS code for each county links to [[U.S. Census Bureau|census]] data for that county.

{{Countytabletop
| region_width      = 120px
| fips_ref          = <ref name="FIPS">{{cite web |url=http://www.epa.gov/enviro/html/codes/tx.html |title=EPA County FIPS Code Listing |work=EPA.gov |access-date=February 23, 2008}}</ref>
| region_seat_width =
| region_seat_title = County seat
| region_seat_ref   = <ref name="NACO">{{cite web|url=http://www.naco.org/Template.cfm?Section=Find_a_County&Template=/cffiles/counties/state.cfm&state.cfm&statecode=MT|title=NACo – Find a county|author=National Association of Counties|access-date=April 26, 2007|url-status=dead|archive-url=https://web.archive.org/web/20050421133035/http://www.naco.org/Template.cfm?Section=Find_a_County&Template=%2Fcffiles%2Fcounties%2Fstate.cfm&state.cfm&statecode=MT|archive-date=April 21, 2005}}</ref>
| data2_width       =
| data2_title       = {{abbr|Est.|Established}}
| data2_ref         = <ref name="NACO"/>
| data3_width       = 
| data3_title       = Origin
| data3_ref         = 
| data4_width       = 
| data4_unsortable  = yes
| data5_title       = License plate prefix
| data5_ref         = <ref>{{cite web |url=https://www.mtcounties.org/counties/county-seats-corresponding-license-plate-numbers/ |publisher=Montana Association of Counties |title=Montana county seats & corresponding license plate numbers |accessdate=January 2, 2022}}</ref><ref name=wtdl>{{cite news |url=https://billingsgazette.com/news/state-and-regional/montana/whats-the-deal-with-montanas-license-plate-numbering-system/article_119837d9-3863-5951-a163-066c86fd86af.html |work=Billings Gazette |title=What's the deal with Montana's license plate numbering system? |date=May 2, 2014<!-- Updated Mar 16, 2021--> |accessdate=January 2, 2022}}</ref><!--<ref>The license plate prefix sequence is derived from the population rank of each county in the 1930 census.</ref>-->
| population_ref    = <ref name="2024CensusEstimate">{{cite web |url=https://www.census.gov/quickfacts/fact/table/MT/PST045219 |title=2024 U.S. Census QuickFacts: Montana |work=U.S. Census Bureau |access-date=March 15, 2025}}</ref>
| 
}}
{{Countyrow|N=30|Num=001| Name=Beaverhead| Seat=Dillon| Data2={{dts|1865|2|2|abbr=on}}| Data3=Original County |Data4=[[Beaverhead Rock]] in the [[Jefferson River]], which is shaped like a [[American Beaver|beaver]]'s head.<ref>{{cite journal|last=Muntmyler|first=L. E.|title=An Enjoyable Water Trip?|journal=Hunter-Trader-Trapper|date=April 1914|page=52|publisher=A. R. Harding|location=[[Columbus, Ohio]]}}</ref>  |Data5=18 |Population=10006| Area=5543| Size=80px}}
{{Countyrow|N=30|Num=003| Name=Big Horn| Seat=Hardin| Data2={{dts|1913|1|13|abbr=on}}| Data3=[[Rosebud County, Montana|Rosebud County]], [[Yellowstone County, Montana|Yellowstone County]] |Data4=[[Bighorn sheep]] in the area.<ref>{{cite book|last=Greene|first=Jerome|title=Stricken Field: The Little Bighorn Since 1876|year=2008|publisher=[[University of Oklahoma Press]]|location=[[Norman, Oklahoma]]|isbn=978-0-8061-3791-9 |page=263|type=Hardcover}}</ref><ref name="The Open Door To Independence"/>  |Data5=22 |Population=12796| Area=4995| Size=80px}}
{{Countyrow|N=30|Num=005| Name=Blaine| Seat=Chinook| Data2={{dts|1912|2|29|abbr=on}}| Data3=[[Chouteau County, Montana|Chouteau County]] |Data4=[[James G. Blaine]] (1830–1893), [[United States Secretary of State]] and presidential candidate.<ref>{{cite web|last1=Fay|first1=Robert|title=Oklahoma Geological Survey|url=http://www.ogs.ou.edu/pubsscanned/guidebooks/GB9.pdf|publisher=Ogs.edu|last2=Branson |first2=Carl|format=PDF|year=1959}}</ref>|Data5=24|Population=6903|Area=4226| Size=80px}}
{{Countyrow|N=30|Num=007| Name=Broadwater| Seat=Townsend| Data2={{dts|1897|2|9|abbr=on}}| Data3=[[Jefferson County, Montana|Jefferson County]], [[Meagher County, Montana|Meagher County]] |Data4=[[Charles A. Broadwater]] (1840–1892), a pioneer in the area and colonel in the [[United States Army]].<ref>{{cite journal|title=Guidebook … Annual Field Conference|year=1962|issue=13|page=143|quote=Townsend, Montana lies in the central part of Townsend Valley at an elevation of 3833 and is the county seat of Broadwater County. The town was named for an official of the Northern Pacific Railroad. The county was named for Colonel Charles A. Broadwater, an early pioneer.}}</ref> |Data5=43 |Population=8302 |Area=1192 |Size=80px}}
{{Countyrow|N=30|Num=009| Name=Carbon| Seat=Red Lodge| Data2={{dts|1895|3|4|abbr=on}}| Data3=[[Park County, Montana|Park County]], [[Yellowstone County, Montana|Yellowstone County]] |Data4=[[Coal]] deposits in the area.<ref name="The Open Door To Independence">{{cite book|last=Hill|first=Thomas|title=The Open Door To Independence|url=https://archive.org/details/opendoortoindepe00hill|year=1915|publisher=Hill Standard Book Company|location=[[Chicago, Illinois]]|page=[https://archive.org/details/opendoortoindepe00hill/page/225 225]}}</ref> |Data5=10 | Population=11498| Area=2048| Size=80px}}
{{Countyrow|N=30|Num=011| Name=Carter| Seat=Ekalaka| Data2={{dts|1917|2|22|abbr=on}}| Data3=[[Fallon County, Montana|Fallon County]] |Data4= [[Thomas H. Carter|Thomas Henry Carter]] (1854–1911), a [[United States Senate|U.S. Senator]] from [[Montana]].<ref>{{cite web|url=http://www.cartercountymt.info/|title=Carter County Montana|website=www.cartercountymt.info|access-date=March 18, 2018}}</ref> |Data5=42 |Population=1399 |Area=3340 |Size=80px}}
{{Countyrow|N=30|Num=013| Name=Cascade| Seat=Great Falls| Data2={{dts|1887|9|12|abbr=on}}| Data3=[[Chouteau County, Montana|Chouteau County]], [[Meagher County, Montana|Meagher County]] |Data4=[[Great Falls (Missouri River)|Great Falls]] of the [[Missouri River]]. |Data5=2 |Population=84523| Area=2698| Size=80px}}
{{Countyrow|N=30|Num=015| Name=Chouteau| Seat=Fort Benton| Data2={{dts|1865|2|2|abbr=on}}| Data3=Original County |Data4=[[Jean Pierre Chouteau]] (1758–1849) and his son [[Pierre Chouteau, Jr.]] (1789–1865). They were part of the [[Chouteau]] fur-trading family. |Data5=19 |Population=5880| Area=3973| Size=80px}}
{{Countyrow|N=30|Num=017| Name=Custer| Seat=Miles City| Data2={{dts|1865|2|2|abbr=on}}| Data3=Original County |Data4=Originally [[Big Horn County, Montana Territory|Big Horn County]],<ref name=Big_Horn_County>[[Big Horn County, Montana Territory]] was not the same county as present day [[Big Horn County, Montana]].</ref> renamed February&nbsp;16, 1877 for [[George Armstrong Custer]] |Data5=14 |Population=11964| Area=3783| Size=80px}}
{{Countyrow|N=30|Num=019| Name=Daniels| Seat=Scobey| Data2={{dts|1920|8|30|abbr=on}}| Data3=[[Sheridan County, Montana|Sheridan County]], [[Valley County, Montana|Valley County]] |Data4=Mansfield A. Daniels (1858 - 1919), an early rancher and storekeeper |Data5=37 |Population=1625| Area=1426| Size=80px}}
{{Countyrow|N=30|Num=021| Name=Dawson| Seat=Glendive| Data2={{dts|1869|1|15|abbr=on}}| Data3=Unorganized lands |Data4=Andrew Dawson, a [[Animal trapping|trapping]] official and major in the [[United States Army]] |Data5=16 | Population=8731| Area=2373| Size=80px}}
{{Countyrow|N=30|Num=023| Name=Deer Lodge| Seat=Anaconda| Data2={{dts|1865|2|2|abbr=on}}| Data3=Original County |Data4=Deer Lodge Valley, which in turn was either named for the Native American name "Lodge of the White-tailed Deer" or a salt lick where [[deer]] came in droves |Data5=30 |Population=9811| Area=737| Size=80px}}
{{Countyrow|N=30|Num=025| Name=Fallon| Seat=Baker| Data2={{dts|1913|12|9|abbr=on}}| Data3=[[Custer County, Montana|Custer County]] |Data4=[[Benjamin O'Fallon]], a Federal [[Native Americans in the United States|Native American]] agent|Data5=39 |Population=2946| Area=1620| Size=80px}}
{{Countyrow|N=30|Num=027| Name=Fergus| Seat=Lewistown| Data2={{dts|1885|3|12|abbr=on}}| Data3=[[Chouteau County, Montana|Chouteau County]], [[Meagher County, Montana|Meagher County]] |Data4=Andrew Fergus (1850 - 1928), one of the first settlers in the county |Data5=8 |Population=11862| Area=4339| Size=80px}}
{{Countyrow|N=30|Num=029| Name=Flathead| Seat=Kalispell| Data2={{dts|1893|2|6|abbr=on}}| Data3=[[Missoula County, Montana|Missoula County]] |Data4=[[Confederated Salish and Kootenai Tribes of the Flathead Nation|Flathead]] [[Native Americans in the United States|Native Americans]] |Data5=7 |Population=114527| Area=5099| Size=80px}}
{{Countyrow|N=30|Num=031| Name=Gallatin| Seat=Bozeman| Data2={{dts|1865|2|2|abbr=on}}| Data3=Original County |Data4=[[Albert Gallatin]] (1761–1849), the [[United States Secretary of the Treasury]] at the time of the [[Lewis and Clark Expedition]] |Data5=6 |Population=126984| Area=2507| Size=80px}}
{{Countyrow|N=30|Num=033| Name=Garfield| Seat=Jordan| Data2={{dts|1919|2|7|abbr=on}}| Data3=[[Dawson County, Montana|Dawson County]] |Data4=[[James A. Garfield]] (1831–1881), the twentieth [[President of the United States]]|Data5=50 |Population=1181| Area=4668| Size=80px}}
{{Countyrow|N=30|Num=035| Name=Glacier| Seat=Cut Bank| Data2={{dts|1919|2|17|abbr=on}}| Data3=[[Teton County, Montana|Teton County]] |Data4=[[Glacier National Park (U.S.)|Glacier National Park]], which borders the county|Data5=38 |Population=13503| Area=2995| Size=80px}}
{{Countyrow|N=30|Num=037| Name=Golden Valley| Seat=Ryegate| Data2={{dts|1920|10|4|abbr=on}}| Data3=[[Musselshell County, Montana|Musselshell County]], [[Sweet Grass County, Montana|Sweet Grass County]] |Data4=Probably named in a promotional attempt to lure settlers to the area |Data5=53 |Population=863| Area=1175| Size=80px}}
{{Countyrow|N=30|Num=039| Name=Granite| Seat=Philipsburg| Data2={{dts|1893|3|2|abbr=on}}| Data3=[[Deer Lodge County, Montana|Deer Lodge County]], [[Missoula County, Montana|Missoula County]] |Data4=Named for the granite rock which is common in the area's mountains and also held the area's rich [[gold]] and [[silver]] ore; the old mining town of [[Granite, Montana|Granite]] shared the name.<ref name=MTPlaceNames>{{cite web|title=Montana Place Names from Alzada to Zortman|url=http://mtplacenames.org/|website=Montana Place Names Companion Website|publisher=Montana Historical Society and Montana State Library|access-date=October 31, 2015}}</ref>|Data5=46 |Population=3602| Area=1728| Size=80px}}
{{Countyrow|N=30|Num=041| Name=Hill| Seat=Havre| Data2={{dts|1912|2|22|abbr=on}}| Data3=[[Chouteau County, Montana|Chouteau County]] |Data4=[[James J. Hill]] (1838–1916), a leading [[railroad]] tycoon |Data5=12 | Population=16065| Area=2896| Size=80px}}
{{Countyrow|N=30|Num=043| Name=Jefferson| Seat=Boulder| Data2={{dts|1865|2|2|abbr=on}}| Data3=Original County |Data4=[[Thomas Jefferson]] (1743–1826), the third [[President of the United States]] |Data5=51 |Population=13304| Area=1657 |Size=80px}}
{{Countyrow|N=30|Num=045| Name=Judith Basin| Seat=Stanford| Data2={{dts|1920|12|10|abbr=on}}| Data3=[[Cascade County, Montana|Cascade County]], [[Fergus County, Montana|Fergus County]] |Data4=The [[Judith River]] which was in turn named by [[William Clark (explorer)|William Clark]] for Julia "Judith" Hancock, whom he would later marry |Data5=36 |Population=2111| Area=1870| Size=80px}}
{{Countyrow|N=30|Num=047| Name=Lake| Seat=Polson| Data2={{dts|1923|5|11|abbr=on}}| Data3=[[Flathead County, Montana|Flathead County]], [[Missoula County, Montana|Missoula County]] |Data4=[[Flathead Lake]] |Data5=15 | Population=33403| Area=1494| Size=80px}}
{{Countyrow|N=30|Num=049| Name=Lewis and Clark| Seat=Helena| Data2={{dts|1865|2|2|abbr=on}}| Data3=Original County |Data4=Originally [[Edgerton County, Montana Territory|Edgerton County]]), renamed March&nbsp;1, 1868 for [[Meriwether Lewis]] and [[William Clark]] |Data5=5 |Population=75129| Area=3461| Size=80px}}
{{Countyrow|N=30|Num=051| Name=Liberty| Seat=Chester| Data2={{dts|1920|2|11|abbr=on}}| Data3=[[Chouteau County, Montana|Chouteau County]], [[Hill County, Montana|Hill County]] |Data4=The sentiment of the inhabitants when the county was formed soon after [[World War I]] |Data5=48 |Population=1934| Area=1430| Size=80px}}
{{Countyrow|N=30|Num=053| Name=Lincoln| Seat=Libby| Data2={{dts|1909|3|9|abbr=on}}| Data3=[[Flathead County, Montana|Flathead County]] |Data4=[[Abraham Lincoln]] (1809–1865), the 16th [[President of the United States]] |Data5=56 |Population=22184| Area=3613| Size=80px}}
{{Countyrow|N=30|Num=057| Name=Madison| Seat=Virginia City| Data2={{dts|1865|2|2|abbr=on}}| Data3=Original County |Data4=[[James Madison]] (1751–1836), the fourth [[President of the United States]] and the [[United States Secretary of State|Secretary of State]] at the time of the [[Lewis and Clark Expedition]] |Data5=25 |Population=9753| Area=3587| Size=80px}}
{{Countyrow|N=30|Num=055| Name=McCone| Seat=Circle| Data2={{dts|1919|2|20|abbr=on}}| Data3=[[Dawson County, Montana|Dawson County]], [[Richland County, Montana|Richland County]] |Data4=George McCone (1853 - 1929), a [[Montana]] state [[United States Senate|senator]] who helped create the county |Data5=41 |Population=1717| Area=2643| Size=80px}}
{{Countyrow|N=30|Num=059| Name=Meagher| Seat=White Sulphur Springs| Data2={{dts|1867|11|16|abbr=on}}| Data3=[[Chouteau County, Montana|Chouteau County]], [[Gallatin County, Montana|Gallatin County]] |Data4=[[Thomas Francis Meagher]] (1823–1867), an [[List of Governors of Montana|acting Governor]] of the [[Montana Territory]] |Data5=47 |Population=2065| Area=2392| Size=80px}}
{{Countyrow|N=30|Num=061| Name=Mineral| Seat=Superior| Data2={{dts|1914|8|7|abbr=on}}| Data3=[[Missoula County, Montana|Missoula County]] |Data4=Many [[mining|mines]] and mining prospects within the county |Data5=54 |Population=5195| Area=1220| Size=80px}}
{{Countyrow|N=30|Num=063| Name=Missoula| Seat=Missoula| Data2={{dts|1865|2|2|abbr=on}}| Data3=Original County |Data4=Supposedly a contraction of the [[Confederated Salish and Kootenai Tribes of the Flathead Nation|Flathead]] word, "im-i-sul-e-etiku", meaning "by or near the place of fear or ambush", a reference to Hell Gate Canyon, in which Flathead [[Native Americans (U.S.)|Native Americans]] were sometimes attacked by [[Blackfoot Confederacy|Blackfeet]] |Data5=4 |Population=122546| Area=2598| Size=80px}}
{{Countyrow|N=30|Num=065| Name=Musselshell| Seat=Roundup| Data2={{dts|1911|2|11|abbr=on}}| Data3=[[Fergus County, Montana|Fergus County]], [[Meagher County, Montana|Meagher County]], [[Yellowstone County, Montana|Yellowstone County]] |Data4=The [[Musselshell River]], named in turn by the [[Lewis and Clark Expedition]] presumably due to [[mussel]]s found on its banks |Data5=23 | Population=5452| Area=1867| Size=80px}}
{{Countyrow|N=30|Num=067| Name=Park| Seat=Livingston| Data2={{dts|1887|2|23|abbr=on}}| Data3=[[Gallatin County, Montana|Gallatin County]] |Data4=Nearby [[Yellowstone National Park]] |Data5=49 | Population=18074| Area=2656| Size=80px}}
{{Countyrow|N=30|Num=069| Name=Petroleum| Seat=Winnett| Data2={{dts|1924|11|24|abbr=on}}| Data3=[[Fergus County, Montana|Fergus County]] |Data4=The production of [[petroleum]] at [[Cat Creek, Montana|Cat Creek]] |Data5=55 | Population=525| Area=1654| Size=80px}}
{{Countyrow|N=30|Num=071| Name=Phillips| Seat=Malta| Data2={{dts|1915|2|5|abbr=on}}| Data3=[[Blaine County, Montana|Blaine County]], [[Valley County, Montana|Valley County]] |Data4=Benjamin D. Phillips (1857 - 1926), a leading rancher and early pioneer in the county |Data5=11 | Population=4214| Area=5140| Size=80px}}
{{Countyrow|N=30|Num=073| Name=Pondera| Seat=Conrad| Data2={{dts|1919|2|17|abbr=on}}| Data3=[[Chouteau County, Montana|Chouteau County]], [[Teton County, Montana|Teton County]] |Data4=Originally ''pend d'oreille'', [[French language|French]] words meaning "[[ear]] pendant"; the name was changed to a form resembling the phonetic spelling to avoid confusion with the lake and town of the same name in Idaho and of a county in Washington.|Data5=26 |Population=6078| Area=1625| Size=80px}}
{{Countyrow|N=30|Num=075| Name=Powder River| Seat=Broadus| Data2={{dts|1919|3|7|abbr=on}}| Data3=[[Custer County, Montana|Custer County]] |Data4=The [[Powder River (Montana)|Powder River]], named in turn for the [[gunpowder]]-like sand on its shores |Data5=9 |Population=1734| Area=3297| Size=80px}}
{{Countyrow|N=30|Num=077| Name=Powell| Seat=Deer Lodge| Data2={{dts|1901|1|31|abbr=on}}| Data3=[[Deer Lodge County, Montana|Deer Lodge County]] |Data4=Mount Powell, which in turn was named for [[John Wesley Powell]] (1834–1902), the early environmentalist and [[explorer]] |Data5=28 |Population=7120| Area=2326| Size=80px}}
{{Countyrow|N=30|Num=079| Name=Prairie| Seat=Terry| Data2={{dts|1915|2|5|abbr=on}}| Data3=[[Dawson County, Montana|Dawson County]], [[Fallon County, Montana|Fallon County]] |Data4=The county's location on the [[Great Plains]] |Data5=45 |Population=1112| Area=1737| Size=80px}}
{{Countyrow|N=30|Num=081| Name=Ravalli| Seat=Hamilton| Data2={{dts|1893|2|16|abbr=on}}| Data3=[[Missoula County, Montana|Missoula County]] |Data4=[[Anthony Ravalli]] (1812–1884), a Jesuit missionary who came to the area in 1845 |Data5=13 |Population=48187| Area=2394| Size=80px}}
{{Countyrow|N=30|Num=083| Name=Richland| Seat=Sidney| Data2={{dts|1914|5|27|abbr=on}}| Data3=[[Dawson County, Montana|Dawson County]] |Data4=Named so as to depict fertile soil, in an attempt to lure in settlers |Data5=27 | Population=11028| Area=2084| Size=80px}}
{{Countyrow|N=30|Num=085| Name=Roosevelt| Seat=Wolf Point| Data2={{dts|1919|2|18|abbr=on}}| Data3=[[Sheridan County, Montana|Sheridan County]] |Data4=[[Theodore Roosevelt]] (1858–1919), the 26th [[President of the United States]] |Data5=17 |Population=10197| Area=2356| Size=80px}}
{{Countyrow|N=30|Num=087| Name=Rosebud| Seat=Forsyth| Data2={{dts|1901|2|11|abbr=on}}| Data3=[[Custer County, Montana|Custer County]] |Data4=The [[Stillwater River (Stillwater County, Montana)|Rosebud River]], which was named for the many [[Rosa acicularis|wild rose]]s along its banks |Data5=29 |Population=8194| Area=5012| Size=80px}}
{{Countyrow|N=30|Num=089| Name=Sanders| Seat=Thompson Falls| Data2={{dts|1905|2|7|abbr=on}}| Data3=[[Missoula County, Montana|Missoula County]] |Data4=[[Wilbur Fiske Sanders]] (1834–1905), a pioneer, vigilante, and [[United States Senate|U.S. Senator]] from [[Montana]] |Data5=35| Population=13895| Area=2762| Size=80px}}
{{Countyrow|N=30|Num=091| Name=Sheridan| Seat=Plentywood| Data2={{dts|1913|3|24|abbr=on}}| Data3=[[Valley County, Montana|Valley County]] |Data4=[[Philip Sheridan]] (1831–1888), [[American Civil War|Civil War]] general |Data5=34 |Population=3448| Area=1677| Size=80px}}
{{Countyrow|N=30|Num=093| Name=Silver Bow| Seat=Butte| Data2={{dts|1881|2|16|abbr=on}}| Data3=[[Deer Lodge County, Montana|Deer Lodge County]] |Data4=Silver Bow Creek; there are multiple theories explaining how the creek was named |Data5=1 |Population=36134| Area=718| Size=80px}}
{{Countyrow|N=30|Num=095| Name=Stillwater| Seat=Columbus| Data2={{dts|1913|3|24|abbr=on}}| Data3=[[Carbon County, Montana|Carbon County]], [[Sweet Grass County, Montana|Sweet Grass County]], [[Yellowstone County, Montana|Yellowstone County]] |Data4=[[Stillwater River (Stillwater County, Montana)|Stillwater River]], ironically named for its very fast current |Data5=32 |Population=9450| Area=1795| Size=80px}}
{{Countyrow|N=30|Num=097| Name=Sweet Grass| Seat=Big Timber| Data2={{dts|1895|3|5|abbr=on}}| Data3=[[Meagher County, Montana|Meagher County]], [[Park County, Montana|Park County]], [[Yellowstone County, Montana|Yellowstone County]] |Data4=The abundant [[Muhlenbergia sericea|sweet grass]] in the county |Data5=40 |Population=3757| Area=1855| Size=80px}}
{{Countyrow|N=30|Num=099| Name=Teton| Seat=Choteau| Data2={{dts|1893|2|7|abbr=on}}| Data3=[[Chouteau County, Montana|Chouteau County]] |Data4=The Teton Range which is in turn named for the French word for 'nipple', ''teton''|Data5=31 |Population=6444| Area=2273| Size=80px}}
{{Countyrow|N=30|Num=101| Name=Toole| Seat=Shelby| Data2={{dts|1914|5|7|abbr=on}}| Data3=[[Hill County, Montana|Hill County]], [[Teton County, Montana|Teton County]] |Data4=[[Joseph Toole]] (1851–1929), the first and fourth [[List of Governors of Montana|Governor of Montana]] |Data5=21 | Population=5153| Area=1911| Size=80px}}
{{Countyrow|N=30|Num=103| Name=Treasure| Seat=Hysham| Data2={{dts|1919|2|7|abbr=on}}| Data3=[[Rosebud County, Montana|Rosebud County]] |Data4=Named promotionally to attract new settlers |Data5=33 | Population=739| Area=979| Size=80px}}
{{Countyrow|N=30|Num=105| Name=Valley| Seat=Glasgow| Data2={{dts|1893|2|6|abbr=on}}| Data3=[[Dawson County, Montana|Dawson County]] |Data4=Much of the county lies within the valley of the [[Milk River (Alberta–Montana)|Milk River]] |Data5=20 |Population=7434| Area=4921| Size=80px}}
{{Countyrow|N=30|Num=107| Name=Wheatland| Seat=Harlowton| Data2={{dts|1917|2|22|abbr=on}}| Data3=[[Meagher County, Montana|Meagher County]], [[Sweet Grass County, Montana|Sweet Grass County]] |Data4=The many [[wheat]] fields in the county |Data5=44 |Population=2058| Area=1423| Size=80px}}
{{Countyrow|N=30|Num=109| Name=Wibaux| Seat=Wibaux| Data2={{dts|1914|8|17|abbr=on}}| Data3=[[Dawson County, Montana|Dawson County]], [[Fallon County, Montana|Fallon County]], [[Richland County, Montana|Richland County]] |Data4=[[Pierre Wibaux]] (1858–1913), a pioneer and cattleman |Data5=52 |Population=911| Area=889| Size=80px}}
{{Countyrow|N=30|Num=111| Name=Yellowstone| Seat=Billings| Data2={{dts|1883|2|26|abbr=on}}| Data3=[[Custer County, Montana|Custer County]] |Data4=The [[Yellowstone River]], named in turn for the yellow rocks found along its shores |Data5=3 |Population=171583| Area=2635| Size=80px}}
|}

===Previous counties===
*[[St. Charles County, Missouri Territory]] created October&nbsp;1, 1812, moved 1813
*[[Vancouver County, Oregon Territory]] created August&nbsp;13, 1848, renamed [[Clarke County, Oregon Territory]] September&nbsp;3, 1849
*[[Clarke County, Washington Territory]] created March&nbsp;2, 1853
*[[Walla Walla County, Washington Territory]] April&nbsp;25, 1854
*[[Spokane County, Washington Territory]] created January&nbsp;29, 1858, abolished January&nbsp;19, 1864
*[[Missoula County, Washington Territory]] created December&nbsp;14, 1860, abolished May&nbsp;26, 1864
*[[Shoshone County, Washington Territory]] created January&nbsp;9, 1861, abolished March&nbsp;3, 1863
*[[Stevens County, Washington Territory]] created January&nbsp;20, 1863
*[[Shoshone County, Idaho Territory]] created February&nbsp;4, 1864

===Extinct counties===
*[[Edgerton County, Montana Territory]] created February 2, 1865, renamed [[Lewis and Clark County, Montana Territory]] March&nbsp;1, 1868.
*[[Big Horn County, Montana Territory]]<ref name=Big_Horn_County/> created February 2, 1865, renamed [[Custer County, Montana Territory]] February&nbsp;16, 1877.

=== County equivalents ===
*[[Yellowstone National Park (part), Montana|Yellowstone National Park (Montana Territory)]] created March&nbsp;1, 1872, divided between [[Park County, Montana]] and [[Gallatin County, Montana]] in 1978.

==See also==
*[[History of Montana]]
**[[Bibliography of Montana history]]
**[[Territorial evolution of Montana]]
**[[Timeline of Montana history]]
*[[List of cities and towns in Montana]]
*[[List of ghost towns in Montana]]
*[[List of places in Montana]]
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== References ==
{{reflist}}

== Further reading ==
* {{cite web |last1=writer |first1=Statf |author-link1= |collaboration= |df= |year=2022 |location= |title=MONTANA COUNTY GOVERNMENT OVERVIEW |url=https://ce.naco.org//app/profiles/CountyGov/CountyGov_30000.pdf |url-access= |format= |department= |website=ce.naco.org |type= |language= |edition= |agency=National Association of Counties (NACo) |arxiv= |asin= |asin-tld= |bibcode= |bibcode-access= |biorxiv= |citeseerx= |doi= |doi-access= |doi-broken-date= |eissn= |hdl= |hdl-access= |isbn= |ismn= |issn= |jfm= |jstor= |jstor-access= |lccn= |medrxiv= |mr= |oclc= |ol= |ol-access= |osti= |osti-access= |pmc= |pmc-embargo-date= |pmid= |rfc= |sbn= |ssrn= |s2cid= |s2cid-access= |zbl= |id= |url-status= |archive-url= |archive-format= |archive-date= |access-date=January 3, 2025 |quote-page= |quote-pages= |quote= |ref= }}

{{Montana}}
{{U.S. Counties}}

[[Category:Lists of counties of the United States by state|Montana]]
[[Category:Montana counties|*List]]
[[Category:Montana geography-related lists|Counties]]