Having last seen it going east on May 11, The Patrón Tequila Express is heading back west on the end of Amtrak #5(17). This California Zephyr is going through Wyoming today.
I've been in several PVs. Worked a handful. And been in several office cats. He's right it's the only way to go. Sometimes on a longer stop you might be able to talk to the owner and he might let you on. It's worked for me in the past.