Mountrail County, North Dakota: History
The Dakota Territory legislature created the county (as Mountraille County) on January 4, 1873, with an area annexed from Buffalo County. The origin of its name came from Joseph Mountraille, a locally famed Metis voyageur and mail carrier from Pembina under Norman Kittson's employment. The county was not organized at that time, nor was it attached to another county for administrative or judicial purposes. The new county lost territory in 1885 when a portion was annexed off to create Garfield County (now extinct). This situation continued until February 21, 1891, when Mountrail County was attached to Ward County for "judicial and other purposes." The following year (November 8, 1892), the North Dakota legislature voted to dissolve the county and have its territory absorbed by Ward County.
An election held in Ward County on November 3, 1908, authorized the re-creation of Mountrail County, although with different boundaries than the previous county proposal. The countywide vote totals were 4207 to 4024, but the result was contested in court. On January 16, 1909, the state Supreme Court upheld the vote,
so the county government was organized on January 29 of that year.
Oil production from the Bakken formation in the early 21st century attracted workers and reversed decades of population decline in the county. From 2010 to 2015, especially, population markedly increased, creating its own strains.