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|Territory: May 26, 1864|
|Statehood: Nov 8, 1889|
|Borders: MD, NJ and PA|
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Today’s Montana counties did not always exist in the present form. They went through many different changes in the space of a few short years. Montana Counties were first formed while part of the Idaho Territory.
Montana Territorial Counties
The Montana Territory was organized on May 26, 1864. There were originally 9 Montana counties when it was first organized as the Montana Territory in 1865.
The State of Montana entered the union as the 41th state on November 8, 1889.
Montana Counties Today
Montana has two consolidated city-counties—Anaconda with Deer Lodge County and Butte with 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 and the rest of it to Park County.
Fun Facts about Montana Counties
Counties by Year
- Beaverhead, Chouteau, Custer, Deer Lodge, Gallatin, Jefferson, Lewis And Clark, Madison and Missoula Counties was the original 9 counties created on February 02, 1865.
- Petroleum County was the last county created on August 27, 1912.
County Size Facts
- Beaverhead County (5,543 sq mi) is the largest county in Montana.
- Silver Bow County (718 sq mi) is the smallest county in Montana.
County Population Facts
- Petroleum County (485) is the least populated county in Montana.
- Yellowstone County (155,634) is the most populated county in Montana.
Montana City Facts
Montana’s 10 largest cities (2010) are:
- Billings (104,170) is in Yellowstone County
- Missoula (66,788) is in Missoula County
- Great Falls (58,505) is in Cascade County
- Bozeman (37,280) is in Gallatin County
- Butte-Silver Bow (33,525) is in Silver Bow County
- Helena (28,190) is in Lewis and Clark County
- Kalispell (19,927) is in Flathead County
- Havre (9,310) is in Hill County
- Anaconda–Deer Lodge County (9,298) is in Deer Lodge County
- Miles City (8,410) is in Custer County
Boundary Changes of Montana Counties from 1848-1950
This Interactive Map of Montana Counties show the historical boundaries, names, organization, and attachments of every county, extinct county and unsuccessful county proposal from 1848 to 1950.
List of Montana Counties
|County||Created||Created From||Named For||County Seat||Notes|
|Beaverhead County||02 Feb 1865||Montana Territory as an Original County||Beaverhead Rock in the Jefferson River, which is shaped like a beaver’s head||Dillon|
|Big Horn County||13 Jan 1913||Rosebud and Yellowstone Counties||Bighorn sheep in the area||Hardin|
|Blaine County||29 Feb 1912||Chouteau County||In honor of James G. Blaine (1830 – 1893), United States Secretary of State and presidential candidate||Chinook|
|Broadwater County||09 Feb 1897||Jefferson and Meagher Counties||In honor of Charles A. Broadwater (1840 – 1892), a wealthy and influential Montana railroad, real estate, and banking magnate||Townsend|
|Carbon County||04 Mar 1895||Park and Yellowstone Counties||Coal deposits in the area||Red Lodge|
|Carter County||22 Feb 1917||Fallon County||In honor of Thomas Henry Carter (1854 – 1911), a U.S. Senator from Montana||Ekalaka|
|Cascade County||12 Sep 1887||Chouteau and Meagher Counties||Great Falls of the Missouri River||Great Falls|
|Chouteau County||02 Feb 1865||Montana Territory as a Original County||In honor of Jean Pierre Chouteau (1758 – 1849) and his son Pierre Chouteau, Jr. (1789 – 1865). They were part of the Chouteau fur-trading famil||Fort Benton|
|Custer County||07 Feb 1905||Montana Territory as a Original County||In honor of George Armstrong Custer (1839 – 1876), a United States Army officer and cavalry commander in the American Civil War and the American Indian Wars. On June 25, 1876, while leading the 7th Cavalry at the Battle of the Little Bighorn in Montana Territory against a coalition of Native American tribes, he was killed along with his entire detachment in an action known as “Custer’s Last Stand”.||Miles City|
|Daniels County||30 Aug 1920||Sheridan and Valley Counties||In honor of Mansfield A. Daniels, an early rancher and storekeeper||Scobey|
|Dawson County||15 Jan 1869||Unorganized Lands||In honor of Andrew Dawson, a trapping official and a major in the United States Army||Glendive|
|Deer Lodge County||02 Feb 1865||Montana Territory as a Original County||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||Anaconda|
|Fallon County||09 Dec 1913||Custer County||In honor of Benjamin O’Fallon, a Federal Native American agent||Baker|
|Fergus County||12 Mar 1885||Montana Territory as a Original County||In honor of Andrew Fergus, one of the first settlers in the county||Lewistown|
|Flathead County||06 Feb 1893||Missoula County||Flathead Native Americans||Kalispell|
|Gallatin County||02 Feb 1865||Montana Territory as a Original County||In honor of Albert Gallatin (1791 – 1849), the United States Secretary of the Treasury at the time of the Lewis and Clark Expedition||Bozeman|
|Garfield County||07 Feb 1919||Dawson County||In honor of James A. Garfield (1831 – 1881), the twentieth President of the United States (1881) until his death by assassination six and a half months later||Jordan|
|Glacier County||17 Feb 1919||Teton County||Glacier National Park, which borders the county||Cut Bank|
|Golden Valley County||04 Oct 1920||Musselshell and Sweet Grass Counties||Probably named in a promotional attempt to lure settlers to the area||Ryegate|
|Granite County||02 Mar 1893||Deer Lodge and Missoula Counties||Granite Peak, the highest point in Montana which also contained a silver mine named “Granite”||Philipsburg|
|Hill County||28 Feb 1912||Chouteau County||In honor of James J. Hill (1838 – 1916), a leading railroad tycoon and the chief executive officer of a family of lines headed by the Great Northern Railway||Havre|
|Jefferson County||02 Feb 1865||Original County||In honor of Thomas Jefferson (1743 – 1826); a statesman, diplomat, architect, and Founding Father, and the third President of the United States (1801-1809)||Boulder|
|Judith Basin County||10 Dec 1920||Cascade and Fergus Counties||Judith River, which was in turn named by William Clark for Julia “Judith” Hancock, whom he would later marry||Stanford|
|Lake County||11 May 1923||Flathead and Missoula Counties||Flathead Lake||Polson|
|Lewis And Clark County||02 Feb 1865||Montana Territory as a Original County||In honor of Meriwether Lewis and William Clark, the famous explorers from the Lewis and Clark Expedition (1804-1806) which was the first American expedition to cross the western portion of the United States||Helena|
|Liberty County||11 Feb 1920||Chouteau and Hill Counties||The sentiment of the inhabitants when the county was formed soon after World War I||Chester|
|Lincoln County||09 Mar 1909||Flathead County||In honor of Abraham Lincoln (1809 – 1865), the 16th President of the United States (1861-1865) during the American Civil War||Libby|
|Madison County||02 Feb 1865||Montana Territory as a Original County||In honor of James Madison (1751-1836), the fourth President of the United States (1809-1817) and the Secretary of State at the time of the Lewis and Clark Expedition||Virginia City|
|McCone County||20 Feb 1919||Dawson and Richland Counties||In honor of George McCone, a Montana state senator who helped create the county||Circle|
|Meagher County||16 Nov 1867||Chouteau and Gallatin Counties||In honor of Thomas Francis Meagher (1823 – 1867), an acting Governor of the Montana Territory||White Sulphur Springs|
|Mineral County||07 Aug 1914||Missoula County||The many number of mines and mining prospects within the county||Superior|
|Missoula County||02 Feb 1865||Original County||Supposedly a contraction of the 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 were sometimes attacked by Blackfeet||Missoula|
|Musselshell County||11 Feb 1911||Fergus, Meagher, and Yellowstone Counties||Musselshell River, named in turn by the Lewis and Clark Expedition presumably due to mussels found on its banks||Roundup|
|Park County||23 Feb 1887||Gallatin County||The nearby Yellowstone National Park||Livingston|
|Petroleum County||24 Nov 1924||Fergus County||The production of petroleum at Cat Creek||Winnett|
|Phillips County||05 Feb 1915||Blaine and Valley Counties||In honor of B.D. Phillips, a leading rancher and early pioneer in the county||Malta|
|Pondera County||17 Feb 1919||Chouteau and Teton Counties||Originally “pend d’oreille”, 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||Conrad|
|Powder River County||07 Mar 1919||Custer County||Powder River, named in turn for the gunpowder-like sand on its shores||Broadus|
|Powell County||31 Jan 1901||Deer Lodge County||Mount Powell, which in turn was named for John Wesley Powell (1834 – 1902), the early environmentalist and explorer||Deer Lodge|
|Prairie County||05 Feb 1915||Dawson and Fallon Counties||The county’s location on the Great Plains||Terry|
|Ravalli County||16 Feb 1893||Missoula County||In honor of Anthony Ravalli (1812 – 1884), a Jesuit missionary who came to the area in 1845||Hamilton|
|Richland County||27 May 1914||Dawson County||So as to depict fertile soil, in an attempt to lure in settlers||Sidney|
|Roosevelt County||18 Feb 1919||Sheridan County||In honor of Theodore “Teddy” Roosevelt (1858 -1919); a colonel in the Spanish-American War as part of the “Rough Riders”, a statesman, writer, and the twenty-sixth President of the United States (1901-1909)||Wolf Point|
|Rosebud County||11 Feb 1901||Custer County||Rosebud River, which was named for the many wild roses along its banks||Forsyth|
|Sanders County||07 Feb 1905||Missoula County||In honor of Wilbur Fiske Sanders (1834 – 1905); a pioneer, vigilante, and U.S. Senator from Montana||Thompson Falls|
|Sheridan County||24 Mar 1913||Valley County||In honor of Philip Sheridan (1831 – 1888), a major general in the American Civil War and fought in later years in the Indian Wars of the Great Plains||Plentywood|
|Silver Bow County||16 Feb 1881||Deer Lodge County||Silver Bow Creek; there are multiple theories explaining how the creek got its name||Butte|
|Stillwater County||24 Mar 1913||Carbon, Sweet Grass, and Yellowstone Counties||Stillwater River, ironically named for its very fast current||Columbus|
|Sweet Grass County||05 Mar 1895||Meagher, Park, and Yellowstone Counties||The abundant sweet grass in the county||Big Timber|
|Teton County||07 Feb 1893||Chouteau County||Teton Range, which is in turn named for the French word “teton”, which means ‘breast’||Choteau|
|Toole County||07 May 1914||Hill and Teton Counties||In honor of Joseph Toole (1851 – 1929), the first and fourth Governor of Montana||Shelby|
|Treasure County||07 Feb 1919||Rosebud County||Named promotionally to attract new settlers||Hysham|
|Valley County||06 Feb 1893||Dawson County||Because much of the county lies within the valley of the Milk River||Glasgow|
|Wheatland County||22 Feb 1917||Meagher and Sweet Grass Counties||The many wheat fields in the county||Harlowton|
|Wibaux County||17 Aug 1914||Dawson, Fallon, and Richland Counties||In honor of Pierre Wibaux (1858 – 1913), a pioneer and cattleman||Wibaux|
|Yellowstone County||26 Feb 1883||Custer County||Yellowstone River, named in turn for the yellow rocks found along its shores||Billings|
List of Old Former / Extinct Montana Counties
Montana contains some counties that no longer exist because they were discontinued, renamed or merged with another county. These are important for genealogy research purposes.
The below counties formerly within the area of the State of Montana no longer exist:
Edgerton County, Montana County, Montana
Created on February 02, 1865 as a Original County by the Territorial Legislature. Edgerton County was renamed to Custer County in 1877.
Big Horn County, Montana County, Montana
Created on February 02, 1865 as a Original County by the Territorial Legislature. Big Horn County was renamed to Lewis and Clark County on December 20, 1867.