The CZ's death was slow, painful, and public. Western Pacific, the weakest of its three operators, was the first to go to the I.C.C. to ask out-in September of 1966. The Commission was on the horns of a dilemma, since the line was clearly demonstrating significant losses, yet the train was running full in summer, with a year-round load factor of 78 percent.
Furthermore, a survey showed a 95 percent approval rating by passengers. Although Rio Grande claimed losses, it still stood firm with pro-passenger Burlington in supporting the train. The I.C.C. deliberated for five months, then ordered Western Pacific to run the train for another year.
WP was back, hat in hand, as that term expired, only to be rebuffed again by the I.C.C., which felt that the railroad was only half-heartedly trying to improve the train's faltering balance sheet.
Then, in May of 1969, the Rio Grande asked to discontinue its portion of the run, citing annual losses of almost $2 million. By now, passengers were finally beginning to desert the CZ, disillusioned by poor timekeeping, deteriorating equipment, and years of discontinuation notices. The end came in February of 1970, when the I.C.C. ruled that the WP could end its segment, with Rio Grande dropping back to tri-weekly runs, connecting at Salt Lake City with Southern Pacific service to San Francisco.
The California Zephyr made its last run just over a month later.