So far as I know the DRGW used its normal managerial discretion to cancel winter service. Keeping the line open during the winter was very expensive. The crude had stopped moving and the other stuff could readily be handled in substitute truck service as needed. ICC did not regulate service unless shippers filed a complaint, and most shippers and receivers probably were happy to get motor carrier service at railroad rates. The only "complaint" I am aware of was the wall board receiver in Farmington who sent the trucks back for reload on to flatcars, but that was probably more a grandstanding gesture than a real complaint.
JBWX