The Denver & Salt Lake Railway was incorporated in 1925 as a reorganization of the Denver & Salt Lake Railroad, which in turn was incorporated in 1912 to take over from the financially failing Denver, Northwestern and Pacific Railway (incorporated 1902).  At that time the D&SL extended from Denver, through the Front Range to Craig, CO.  The Denver & Rio Grande Western Railroad bought control of the D&SL and built the Dotsero Cutoff, a connection between the D&SL at Orestod and the D&RGW at Dotsero.  The D&SL was officially merged into the D&RGW in 1947.  The subdivisions of the D&SL, 1 and 2, became the D&RGW Pueblo subdivisions 1 and 1A.