Locomotive No. 343 started life on the Denver & Rio Grande Railway
as Class 70 road number 403 and carrying the name "Roaring Forks"
which was soon changed to "New Mexico”. The 403 went to work
alongside the cadre of Class 56 and 60 consolidations pulling
the late 19th century ladings over Marshall Pass and the Gunnison
Extension. Through many years of service, the 403 underwent typical
conversions with the addition of automatic couplers, an electric
headlight, boiler replacement, as well as numerous cosmetic changes
ranging from cabs to smokestacks. Engine 403 was re-numbered 343
in 1924 during the D&RGW power re-classification and was then
given the C-19 designation. The locomotive and two of its
sister class C-19s were leased to the Colorado and Southern
narrow gauge line during the lean depression years between
1936 and 1937 to assist the ailing railroad in its motive
power deficit. No. 343 remained in its D&RGW livery and
paint throughout this time period with the only change being
the addition of the well-known C&S style Ridgway Spark Arrestor.
The 343 rolled through C&S country to Leadville wearing its D&RGW
Royal Gorge Route herald scheme until April of 1937. As the end
of operations was rapidly approaching for the C&S, the C-19s were
returned to the D&RGW by flatcar to Alamosa. After 60 years of
service, the 343 ultimately met the scrappers torch in the spring of 1941.