There are some maps but they are not detailed and just show the general area where the route was to go. One was to build over ohio pass to the North Fork of the Gunnison River and follow it to the Colorado River, there was another through the Black Canyon with a branch to Lake City, One to Ouray, and a line running in the direction of the San Juans where the RGS would be one day. None of it never happend when they came in second to Gunnison.
Two fatal mistake made by the South Park was not building up the Arkansas valley to Leadville after beating the Grande to Buena Vista and deciding Marshall pass was to steep for a railroad. These mistakes are what killed the South Park in the long run, just imagine if it was the DSP&P that built over Tennessee pass and Marshall instead of the D&RG.
Alex