The Missoulian was established as the Missoula and Cedar Creek Pioneer on September 15, 1870,[2] by the Magee Brothers and I. H. Morrison, under the Montana Publishing Company.

Hammond's purchase of The Missoulian brought the newspaper into the republican fold and on the battle lines of the William A. Clark and Marcus Daly Copper Kings feud.

Hammond had become very wealthy over-logging unsurveyed public timberland and supplying lumber to the railroad and Daly's Anaconda Company's smelter.

Hammond and his associates in Missoula convinced Daly to thwart Clark's 1888 bid for the Montana Territory's At-large congressional district and support Republican Thomas H. Carter instead.

[6][7] Daly's election maneuvering created a major rift between the Copper Kings, and the next year he became chairman of the Montana Democratic Party.

[6][7] In 1900, Hammond began selling stock in the Missoulian to political rival Joseph M. Dixon, who later became a US Congressman, US Senator, and the state of Montana's seventh governor.

[9][6] The Republican Daily Missoulian (as it was called until 1961) was soon rivaled by the Democrat-leaning Missoula Herald, published by the Hassler Brothers and its successor, the Missoula Sentinel, that was purchased in 1912 (one year after its founding) by Richard Kilroy for the purpose of politically wounding Dixon, as he ran for re-election in the first year Senators were popularly elected.

The Missoulian was not a "Company paper"; according to Jerre Murphy, a former Amalgamated employee turned muckracker, it was the only major newspaper in Montana that was not.

Two newspapermen from the Chicago Journal, Martin Hutchens and Lester L. Jones, purchased the Missoulian and were soon part of the "copper press" (i.e. a "Company paper" known for using its pages to promote the Company's views and for suppressing news it didn't want reported) and remained as such, until Anaconda Copper sold all its Montana newspapers to Lee Enterprises, in 1959.

He and Lee Enterprises' CEO, Phillip Adler, successfully purchased the papers despite not being the highest bidders with an agreement made in late May.

[6] While most of Lee Enterprises' new newspapers retained their leadership, the Missoulian was an exception, where Lloyd Schermer, son-in-law of Phillip Adler, took over as publisher.

[17] The weekly newspaper was then purchased by the Fruit-Grower Publishing Company and existed as a horticulture and general news publication, until the mid-1910s.