From Denver to Limon has always been a Union Pacific line. Colorado
Springs to Limon is abandoned. Limon east to McFarland and Mahaska was taken over by Kyle
Railways after the Rock Island bankruptcy in 1980. From Mahaska (between
Belleville and Fairbury), the line to Omaha was abandoned.
Summit to Council Bluffs has always been Union Pacific. The line east of
Council Bluffs is now Iowa Interstate into Illinois, who also operate all the
way to Blue Island. CSX owns the line from Bureau to Joliet, where Metra
ownership takes over..