Latterly, yes. It started off as a premium train between LA and Portland in the '30's.
Make that Chicago...... it ran attached to the Los Angeles Limited as far as either Omaha, Cheyene or Green River depending on the year.
History of UP's 'City' trains makes for a fascinating read, at one stage there were 4 or 5 City trains all leaving Chicago as one train. They would split en route once on the UP proper, which was Omaha-Ogden-LA
Other trains would also combine along the way. UP worked with other roads to make this all happen. Originally Omaha-Chicago was with CNW, but they teamed up with Milwaukee Road in the 50's.
Southern Pacific facilitated UP transit into San Francisco. UP owned their own routes to LA, Denver, and Portland. Of course, UP now own SP, CNW, and D&RGW, and run commuter operations for one of the Metro authorities in Chicago.
OK, that was a ramble from memory. I'll check my facts, and amend any errors I've made. In a clean up at work, many years ago, I scored a March 1971 Official Guide for the American railroads. Never paid that much attention to it, until recently after reading a story about the 'City of Everywhere'..... Google it, interesting.