1949 Speed Limits:
Alamosa-Antonito 40 pass, 30 frt
Antonito-Lava 40 pass, 25 frt.
Cumbres-MP-342.8 Descending 18 pass, 12frt.
Cumbres-Lava 30 pass, 18 frt.
Sharp Curves 20 pass, 15 frt.
Cumbres-Antonito Snow Plow Trains 25 pass, 25 frt.
Sharp Curves Snow Plow Trains 18 pass 18 frt.
Over Bridges 319.95 and 339.78 10 pass, 10 frt.
K-36 and K-37 classes are limited to 35mph.
Note: I could not find a definition of a "Sharp Curve". Nor have I seen any other references to "Passenger Snow Plow Trains" vs. "Freight Snow Plow Trains".
1963 Speed Limits
Alamosa-Antonito 35 pass, 30 frt.
MP 286-MP 290 20 pass,15 frt.
MP 290-307 25 pass, 18 frt.
MP307-321 15 pass, 12 frt.
MP321-Cumbres 15 pass, 15 frt.
Cumbres-Chama 15 pass, 12 frt.
Over bridge 319.95 8 pass, 8 frt.
Over bridge 339.78 10 pass, 10 frt.