Mississippi River and Bonne Terre Railway

The Mississippi River & Bonne Terre Railway (M.R. & B.T.) was a single-track standard-gauge steam railroad that was located in southeastern Missouri and began service in 1892. It extended from Riverside in a general southwesterly direction to the lead-mining field in St. Francois County. The main stem, from Riverside to Doe Run, was long. Eight short branch lines had a total trackage of . Sidings and spurs aggregated , and all tracks owned .
Corporate history.
Predecessors.
The minerals and supplies of the St. Joseph Lead Co., which operated one of the world-leading lead mines, were transported until 1880 on animal-drawn wagons between the mines and the St. Louis and Iron Mountain Railway. In 1880 the St. Joseph Lead Company laid the track a long narrow gauge railroad with a gauge of . It was inaugurated on 18 January 1880 and became known as the St. Joseph & Des Loge Railway. It was used to transport goods westerly from Bonne Terre to Summit, a point on the line of the St. Louis, Iron Mountain & Southern Railway Company, but the mine products of the St. Joseph Lead Company had still to be hauled for by ox-team from the mines to Bonne Terre. The narrow-gauge line was apparently jointly owned by the St. Joseph Lead Company and the Desloge Company. It was removed after the M.R. & B.T.'s property was placed in service. The cost was split between both companies: The St. Joe paid 66% and the Desloge Company paid 33%. The St. Joe Lead Company acquired in 1887 the assets of the Desloge Lead Company, and tried to find a shorter route, to reduce the transportation cost.
M.R. & B.T..
The M.R. & B.T. was incorporated for a term of 50 years on May 11, 1888, under the provisions of Chapter 21, Articles 1 and 2, of the revised statutes of Missouri. The incorporators were nominees of the St. Joseph Lead Company. The avowed purpose of the corporation was to construct, operate, and maintain a standard or broad gauge railroad, extending in a northerly direction from Bonne Terre, St. Francois County, through St. Francois and Jefferson Counties, in Missouri, to a point on the Mississippi River now known as Riverside. The proposed line was long, and the authorized capital stock had the value of $10,000 per mile, or $300,000.
The railway was initially constructed as a narrow gauge railroad between Bonne Terre and Riverside, a wharf at the Mississippi River. The first section was inaugurated in 1890 and the Summit Railroad was subsequently abandoned. In 1894 the gauge of the railroad was re-gauged to standard gauge and later the track was expanded from Bonne Terre to Doe Run. It crossed the Belmont Branch of the Iron Mountain Railway at Doe Run Junction.
The main line of the Mississippi River and Bonne Terre Railroad was, after completion, only long, but it proved to be beneficial for the development of the Lead Belt, since there was a lot of traffic on the railroad. It was built similar to most trunk lines. A branch line was laid to Leadwood and there were several miles of feeders, turn-offs and sidings. The railroad ran through the growing towns of Bonne Terre, Desloge, St. Francois, Flat River, Rivermines, Elvins and Doe Run, whose economy benefited from the improved transport capabilities.
The inclines were below 1.8% and the curves had radii of . The rail weights ranged between 75–90 lb/yard (37.5–45 kg/metre) similar to most trunk lines. Even so, the order for two Baldwin 4-6-2 Pacific locomotives included the following caution: "Engine frames to be extra heavy throughout. Engine frames to be designed to withstand rough usage and considerable lateral thrust, which will be continually in evidence given that the road is all curves, there being only one tangent [straight track] which is a mile long."
The following amendments to the original charter have been filed: 
The M.R.& B.T.'s main line from Riverside to Bonne Terre, , was constructed for it by the St. Joseph Lead Company during 1889 and 1890. It was placed in regular service on March 10, 1890. The extension of the main line from Bonne Terre to Doe Run Junction, , was also built by the St. Joseph Lead Company for the M.R. & B.T. It was placed in service in June, 1892. The southerly end of the main stem, extending from Doe Run Junction to Doe Run, , was built, during 1892, by the Doe Run Lead Company, a subsidiary of the St. Joseph Lead Company. It was operated by the M.R. & B.T. under lease until September, 1893, when it was purchased outright. The foregoing of line were originally built as narrow gauge, but was changed to standard gauge in 1893–1894. 
The four branch lines, embracing , were constructed as standard gauge as follows:
Aftermath.
The Missouri Pacific acquired the M.R. & B.T. in 1929 and merged it with the Missouri-Illinois Railroad, which operated it as an independent subsidiary until 1945. In 1938 a gasoline passenger train operated and made two round trips per day. The Missouri Pacific Railway subsequently acquired 51% of the Missouri–Illinois Railroad, with which it merged in 1978.
The section from Derby at the junction with the Missouri-Illinois Railway to Doe Run ceased operations in 1941. The section from Howe to Bonne including the tunnel were disused in 1969. The two sections up north and south of Bonne Terre were still in use in the late 1980s.