The Colorado & Rio Grande Southern is a factious Railroad that is a consortium of the major Railroads that banded together and pooled their resources to operate as a single system in the early 1900's to continue operation through the depression and to compete with the fledgling interstate trucking industry.

The Colorado & Rio Grande Southern is made up the Denver & Rio Grande Western, The Colorado & Southern, The Rio Grande Southern and Florence & Cripple Creek. In order to use resources and expenditures in a frugal manor, no attempt was made to re-letter equipment except on newly purchased or built equipment other than passenger equipment which carries the consortium name.

Trains can be seen with rolling stock lettered for any or all of the Narrow Gauge Railroads in the consortium.