Complex sentence: The railroad's flagship passenger train, the "Phoebe Snow", traveled via the Cut-Off until it was discontinued in November 1966, and the last regularly scheduled passenger train ran over the line in early January 1970.
Split into simpler sentences: The railroad's flagship passenger train, the "Phoebe Snow", traveled via the Cut-Off until November 1966, when it was discontinued. The last regularly-scheduled passenger train ran over the Cut-Off in early January 1970.