. UP's president Charles Adams was in favor of cooperation and harmony, completely opposite of his predecessor Jay Gould who wanted to pursue raw competition at every opportunity. Gould had sold most of his interest in Union Pacific in 1881 and turned his attention to fight in other locations.
Gould's rival for rail traffic in the Pacific Northwest, Henry Villard, controlled both the Oregon Railway & Navigation and Northern Pacific. But by 1883 he had developed his own set of financial woes and sold his NP interests in December 1883. With Adams as UP president, and with both Villard and Gould out of the picture, UP and NP agreed to cooperate in moving the Butte mining traffic.
In July 1886 U&N converted its three-foot narrow gauge line between Butte and Garrison (51 miles) to standard gauge, and Montana Union Railway was organized as a joint company to operate the newly converted line in the joint interest of UP and NP. The two roads were also cooperating west from Wallula, Washington along the Columbia River to Portland. Utah & Northern never did get its line to Helena.
The Stuart Line - Stuart To Anaconda
A separate company known as the Montana Railway was organized on December 17, 1881 as a subsidiary of Jay Gould's Union Pacific Railway to serve as its vehicle to control the Montana mining traffic, and keep that same traffic out of the hands of Henry Villard's Northern Pacific. It's stated goal was to build a line between Butte and Helena. Instead, Utah & Northern itself built the line to Garrison as narrow gauge. The Union Pacific line east from Garrison to Helena was not completed.
Montana Railway was held by Union Pacific without trackage or equipment for a year, until late 1882, at which time it was activated to build a new rail line to the new Anaconda smelter and reduction works being built west of the U&N line between Butte and Garrison. The new railroad line, almost nine miles long, opened for business on October 1, 1884. The connection with Montana Union was at Stuart, 35 miles south of Garrison, and 16 miles west of Butte. (Anaconda, by Isaac Marcosson, pages 51-53; Union Pacific Railway and Auxiliary Companies, 1886, page 74; Google Books)
The smelter site was first known as Copperopolis, but was changed to Anaconda by its first postmaster. Construction on Anaconda's new smelter began in late 1882 and full production began in September 1884. The smelter and reduction works was built by Marcus Daly and his associates to process the ores from their mines in Butte, the largest of which was the Anaconda Mine. To further consolidate their interests, they organized the Anaconda Mining Company in January 1891. The Anaconda Reduction Works at the new town of Anaconda, Montana Territory, went into operation to reduce and concentrate the silver ore and copper ore being mined at the Anaconda claim in Butte. The copper ore was extremely rich at eight to ten percent copper. (Anaconda, by Isaac Marcosson, pages 52-53)
On February 15, 1887, as part of its annual report for the year ending November 30, 1886 to the Auditor of the Territory of Montana, Montana Railway gave its route as being nine miles in length, with no double track. The entire length was three-rail track, being both standard gauge and three-foot narrow gauge. The company reported that it owned no locomotives or rolling stock; "The equipment of Utah and Northern Ry. used on this road." The company also reported that it carried 21,152 passengers, no through freight, 221,930 tons of local freight and 202,772 tons of freight that consisted on ore, cattle or grain. "This road was operated by the Montana Union Ry. Co. subsequent to July 31, 1886." (Montana Railway "Railroad Report" to the Auditor of the Territory of Montana, dated February 15, 1887, photocopy furnished by Thorton Waite)
On June 30, 1897 the Montana Railway was sold to the Northern Pacific Railway, as part of the reorganization of Union Pacific in the 1893-1898 time period. The Stuart line was owned and operated by NP after 1897, as part of NP's operation of its lease of Montana Union, giving NP