Denver and Rio Grande Railroad, with both reaching Buena Vista in early 1880. The Denver, South Park and Pacific completed construction first, but rather than both companies laying track to Leadville, Jay Gould pressured the two companies to make a deal called the "Joint Operation Agreement" of October 1, 1879. The companies agree that "...for the purpose of harmony and mutual profit...", the Denver and Rio Grande would lay tracks to the north from Buena Vista to the Leadville mining district, but that the Denver, South Park and Pacific would share equal traffic rights. Similarly, the Denver, South Park and Pacific would build into the Gunnison Country via Chalk Creek, with equal traffic rights given to the Denver and Rio Grande. In 1884 the D&RG ended the Joint Agreement, which forced the DSP&P to build their own line to Leadville. This route, the "High Line" left the original route at Como, and proceeded across Boreas Pass to Breckenridge, then across Fremont Pass to Leadville. This route was noteworthy for crossing the Continental Divide twice (from the Atlantic side to the Pacific side at Boreas Pass, and back to the Atlantic side at Fremont Pass), and was extremely difficult to operate in winter.
