The Idaho Northern Railroad built a branch line of the Oregon Railroad and Navigation Company (OR&N) in northern Idaho, U.S., connecting the main line at Enaville (Now considered a populated place in the unincorporated community of Kingston, Idaho) with Paragon (Formerly located on the Idaho side of the Idaho-Montana state line between Murray, Idaho, and Thompson Falls, Montana), a distance of . The company was incorporated on January 10, 1906, and opened on August 1, 1909 as an operating subsidiary of the Union Pacific Railroad (UP), owner of the OR&N.<ref>Interstate Commerce Commission, Twenty-Third Annual Report on the Statistics of Railways in the United States for the Year Ending June 30, 1910, p. 238 On December 23, 1910, the property of the OR&N and Idaho Northern Railroad were conveyed to new UP subsidiary Oregon–Washington Railroad and Navigation Company.
The line was cut back from Paragon to Prichard after a December 1917 washout. A flood in December 1933 severely damaged the remainder of the line, and the Interstate Commerce Commission authorized its abandonment in 1935.[1] [2] Abandonment allowed for the widening and construction of present day Coeur d’Alene River Road.