Question: What courthouse was built in 1913 in a town established in 1876?

Context paragraphs:
Sheridan County Courthouse (Sheridan, Wyoming): The Sheridan County Courthouse, located at the intersection of Burkett and Main Streets in Sheridan, is the seat of government of Sheridan County, Wyoming.  Built from 1904 to 1905, the courthouse was the first built in the county.  The firm of Link & McAllister designed the courthouse; their design features elements of the Classical Revival and Beaux-Arts styles.  The courthouse is topped by an octagonal dome with oval and rectangular windows and a balustrade.  The building's entrance features a pediment and frieze supported by two Ionic columns.  In 1913, a jail with a sheriff's residence was added to the courthouse site; this building has a similar design to the courthouse.

Forsyth, Montana: Forsyth is a city in and the county seat of Rosebud County, Montana, United States.  The population was 1,777 at the 2010 census.  Forsyth was established in 1876 as the first settlement on the Yellowstone River, and in 1882 residents named the town after General James William Forsyth who commanded Fort Maginnis, Montana during the Indian Wars and the 7th Cavalry at the Wounded Knee Massacre.  The town has long been a transportation nexus, starting with steamboats on the river and progressing to the Northern Pacific Railway and Interstate 94.

Martin County Courthouse (Indiana): Martin County Courthouse is a historic courthouse in Shoals, Indiana.  The courthouse was built in 1876 to replace the previous courthouse, which burned down in the same year.  At the time of the courthouse's construction, Shoals had only been the county seat for seven years, and it was the ninth county seat in Martin County.

Rosebud County Courthouse: The Rosebud County Courthouse, located on Main St. between 12th and 13th Avenues in Forsyth in Rosebud County, Montana, was built in 1913.  It was listed on the National Register of Historic Places in 1986.

Old County Courthouse: The Old County Courthouse (also known as the Plymouth Old County Courthouse or the Old Town House) is an historic court house on Leyden Street and Market Street in the Town Square of Plymouth, Massachusetts.  Built in 1749, the two story wood frame building is believed to be the oldest wooden courthouse in the United States; it stands on the site of the first (1620) courthouse built by Plymouth Colony settlers, and may incorporate elements of a 1670 building.  It is five bays wide and three deep, with a center entry flanked by sidelight windows and pilasters, and topped by a gabled pediment.  It was built by Peter Oliver, and initially served as both a courthouse and as town offices.  It was converted to solely municipal use in 1821, and had a myriad of municipal functions since then.  In the 1970s it was converted into a museum.

Clay County Courthouse (Illinois): The Clay County Courthouse, located at 300 Broadway Street in Louisville, is the county courthouse serving Clay County, Illinois.  Built in 1913, the courthouse was Clay County's fourth courthouse; it has served continuously as the seat of Clay County government since its opening.  Architect Joseph W. Royer, who planned several other Illinois courthouses, designed the Classical Revival building.  The courthouse was added to the National Register of Historic Places in 2015.

Madison County Courthouse (Madison, Florida): The Madison County Courthouse, built in 1913, is an historic courthouse building located in Madison, Florida.  It is Madison County's fourth courthouse and the third built in Madison.  The first log building at San Pedro was abandoned along with the town.  The second courthouse built in 1840 in Madison burned in 1876 and was replaced by an 1880 brick structure which burned in 1912.  The present building is unusual among Florida courthouses of its vintage in never having been added onto or expanded.  In 1989, the Madison County Courthouse was listed in "A Guide to Florida's Historic Architecture", published by the University of Florida Press.

Henderson County Courthouse (Texas): The Henderson County Courthouse, built in 1913, is an historic 3-story redbrick Classical Revival style courthouse building with full basement located at 100 East Tyler Street in Athens, Texas.  The courthouse has been designated as a Recorded Texas Historic Landmark since 2002.  Designed by L. L. Thurman, who also previously designed the Jeff Davis County Courthouse in Fort Davis, it is unusual for its angled wings.  It also has a central cupola which is not seen in most images, but there is no rotunda under the cupola.  It is Henderson County's fourth courthouse and the second in Athens.  The first one was built in 1850 in Buffalo, now a ghost town, and the second was built in 1861 in Centerville, which is also a ghost town today.  The third courthouse was built in Athens in 1887.

Old Grafton County Courthouse: The Old Grafton County Courthouse is a historic courthouse building at 1 Court Street in Plymouth, New Hampshire.  This modest wood frame building was built in 1774 to serve as one of two courthouses for Grafton County, which had just been established; it is one of the oldest surviving civic structures in the state.  It was described at the time of its construction as having "a stately cupola out of proportion to the diminutive size of the structure".  After a new courthouse was built in 1823, the building was sold and moved to the outskirts of Plymouth, and used as a wheelwright's shop, undergoing significant alteration to accommodate that function.  In 1876 the building was acquired by the Young Ladies' Library Association, which moved it to its present location and restored it (except the cupola, of which a replica was added sometime before 1906).  It is now the museum of the Plymouth Historical Society.

Van Wert County Courthouse: The Van Wert County Courthouse is a historic governmental building in downtown Van Wert, Ohio, United States.  Located at 121 E. Main Street, the courthouse is a Second Empire structure built in 1876.  It is Van Wert County's third courthouse: when the county was established, the village of Willshire was designated the county seat; Van Wert was made the seat in 1838, and a courthouse-and-jail complex was built in that community in the following year.

Supporting paragraphs: Rosebud County Courthouse Forsyth, Montana
Answer: Rosebud County Courthouse