[1] The 1903 Pittsburg Coal Diggers became members of the eight–team Class D level Missouri Valley League.
[2][3][4] The Coal Diggers joined the Fort Scott Giants, Iola Gaslighters, Joplin Miners, Leavenworth White Sox, Nevada Lunatics, Sedalia Gold Bugs and Springfield Midgets in beginning league play on May 15, 1903.
[5] In their first season of play, the Pittsburg Coal Diggers placed 6th in the Missouri Valley League standings.
[4] The Muskogee Reds disbanded on August 31, causing the Missouri Valley League to end play on September 5, 1905.
The Pittsburg "Champs" joined the Bartlesville Indians, Chanute Browns, Coffeyville Bricks, Fort Scott Giants, Independence Coyotes, Iola Grays and Parsons Preachers in beginning league play on May 3, 1906.
[4] The Pittsburg Champs/Vinita of the Kansas State League ended their 1906 season with a record of 30–25, as Henry Bartley served as manager in both locations.