Original California Zephyr over Donner

From: "Andy Payne" atpayne2000@sbcglobal.net

I was recently discussing with a friend who travels on the Amtrak California Zephyr frequently his travels on the original California Zephyr. He noted that the time he took the California Zephyr from the east to California, they went via Donner Pass. Now I am familiar with the respective routes of the City of San Francisco and California Zephyr, and have not heard of the California Zephyr taking Donner instead of Feather River. Have there been any instances where the WP would use SP's Donner Pass? ...

—Andy