Looking at the D&RGW profiles, which contain curvature data, I offer the following.
Sharpest curves on Marshall Pass were the 25 degree 30 minute curves between Marshall Pass and Shawano. The sharpest curves anywhere on the D&RGW system where the big engines were used. The K-37 class were regulars for moving Crested Butte coal over the pass.
Salida - Gunnison. 24 degrees between Shirley and Marshall Pass, 25 degrees 30 minutes between Marshall Pass and Shawano, 24 degrees between Shawano and Buxton.
Salida - Alamosa. 20 degrees between Mears Jct. and Poncha Pass.
Alamosa - Chama. 20 degrees between Big Horn and Lobato.
Chama - Durango. 24 degrees between Monero and Amargo.
Silverton Branch. 24 degrees between Hermosa and Cascade.
Farmington Branch. 7 degrees between Carbon Jct. and Colomex (state line).
Monarch Branch. 24 degrees between Maysville and Monarch.
Crested Butte Branch. 16 degrees between Gunnison and Almont, and between Jack's Cabin and Crested Butte.
Hope this helps.
CVM
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