In 1904, the National Car Company delivered to the Denver & Rio Grande 2 classes of drop bottom gondolas, #700 to 799, and #800 to 899 with higher sides and used as coke cars. Both classes have been rebuilt in 1918 with a simpler opening mechanism and the coke cars of the 800 class have been converted to simple drop bottom gondolas. About three quarters of these cars survived until 1967, and today 43 are preserved on the Durango & Silverton Narrow Gauge Railroad, 17 on the Cumbres & Toltec Scenic Railroad and 3 at the Colorado Railroad Museum.
Between 1916 and 1928, the Denver & Rio Grande Western also used 41 Ingoldsby dump cars, originally built for the Crystal River Railroad. In the fifties, the development of the oil industry in the Farmington area brought a lot of traffic to the Rio Grande, to deal with it the railroad had to convert about a hundred of high side gondolas into pipe gondola for the transport of drilling pipes. Since these pipes were longer than the gondolas, the ends of the cars had to be removed and the hand brake wheel shifted to the side. Seven of these pipe gondolas are conserved today on the Cumbres & Toltec Scenic Railroad. In addition, about another hundred of high side gondolas has been converted to idler flat cars in 1955. Also in 1955, the D&RGW had 20 40ft standard gauge box cars transformed into open end gondolas to carry drilling pipes. They received narrow gauge Bettendorf trucks and were numbered from 9600 to 9619. Six of these gondolas have been converted to open observation cars for the Silverton train in 1963 and 1967. The remaining cars were also converted to open observation cars later, for the Durango & Silverton Narrow Gauge Railroad as well as two for the Cumbres & Toltec Scenic Railroad.