The Rio Grande was a strong example of mountain railroading, with a motto of Through the Rockies, not around them and later Main line through the Rockies, both referring to the Rocky Mountains.
the rio g,RanDe WAs a stRonG ExAMPle Of mounTAIn railrOADinG, WiTh a mOTto Of thROugh ThE RoCkiEs, noT arOUnd them aNd lAter main lInE thrOUgh the rockies both reFERRing to the RoCKY MountaINs.