The MMBR was incorporated February 26, 1917 in Oklahoma and June 27, 1917 in Kansas.[1] Its sole stockholder was T.B. Slick, and it was headquartered in Oklahoma City.[1] It was created with the active participation of the Frisco, which wanted a share of the transportation trade in a very productive mining area.[2] Toward that goal, the Frisco provided and leased the rails to the railroad’s creators, and guaranteed a 10% return on construction and equipment costs until a 110% payout on investment had been reached.[3] The Frisco, and its affiliated Kansas City, Fort Scott and Memphis Railway, also leased locomotives and rolling stock to the MMBR.[1] The line traveled westerly, northerly, and northeasterly from Quapaw, Oklahoma through Picher, Oklahoma and on to Baxter Springs, Kansas, 11.05 miles, forming a loop through the Miami and Picher lead mining areas.[2][3] The railway started operation July 6, 1917.[3][4] Including various side, yard, and spur tracks which totaled 29 miles in 1929, the railroad eventually included about 40 miles of trackage.[5] Despite the name, it never ran to Miami, Oklahoma, which was to the southwest.[2][6]
The line was essentially a switching operation to gather traffic from mine and mill spurs and haul it to the Frisco interchange points at Quapaw and Baxter Springs.[3] Most of the traffic was outbound lead and zinc ores, but the line did handle some inbound merchandise as well as passengers.[2][3]
While Frisco was given ICC permission to acquire the line in 1923,[3] it appears Frisco leased the line instead,[2] only acquiring the stock of the carrier on July 31, 1929.[5] Effective January 1, 1930, the line was leased back to the Frisco,[7] where for Frisco’s internal purposes it became the Picher Branch of the Afton Sub-Division of the Northern Division.[7] The line was not officially absorbed into the Frisco until mid-1950.[2][8]