Thanks everyone for your tips.

I wanted to share my experience in the hopes it may be helpful to someone.

Here's the most important thing I want to point out.

THE WESTBOUND CALIFORNIA ZEPHYR REGULARLY LEAVES SACRAMENTO MUCH EARLIER THAN SCHEDULED.

I of course agree with Bob H, but Amtrak doesn't see it this way.

We arrived at Sacramento at 1:35 p.m. or so, and the timetable says it departs Sacramento at 2:13 p.m.

My wife and I hopped off the train and planned to take a 30 minute walk, maybe get a glimpse of the State Capitol.

I asked the attendant "We leave at 2:13 right?" and she said "No! Don't go anywhere"

She explained that this long distance train doesn't sell tickets from Sacramento and points west into Emeryville. That route is covered by commuter trains.

This means no one boards the westbound California Zephyr in Sacramento. So if the train arrives in Sacramento early, which commonly happens, it lets off the departing passengers, and then it continues on a few minutes later towards Emeryville, without regard for the scheduled departure time.

We were running early; we only stopped for five minutes in Sacramento. If I hadn't checked with the attendant I would have surely missed the train, as I was planning to walk off and return fir the 2:13 scheduled departure.

We reached Emeryville an hour early, at 3:10 instead of 4:10. My wife and I then took a $30 Uber to Fisherman's wharf.

Many other passengers booked destinations in San Francisco via the Amtrak connecting bus. But because our train arrived in Emeryville an hour early, they were told they had to wait an hour for the connecting bus to arrive at 4:10.

I recommend this Denver to Emeryville train ride. It's very scenic, you meet interesting people. Definitely get a bedroom or roomette, especially if there are two of you. We paid $613 for the roomette for two passengers, but that included breakfast, lunch, dinner, breakfast and lunch. Five meals for two people = ten meals, including beverage and dessert with lunch and dinner. If we had booked coach seats and ordered the meals a la carte, we would have easily spent over $300 on food. The food was actually pretty good, too.

I do wish they planned the stops better to accommodate tourists and give us a chance to get off the trains and visit interesting towns during stopovers. Glenwood Springs and Truckee both looked interesting, with the town right next to the train station, but we only stopped for under 5 minutes in each town. Instead, we had an hour stop in Salt Lake City, at 11 p.m., and the station is in the "middle of nowhere" with nothing of interest within walking distance.

We also stopped for about 30 minutes in Grand Junction, and the train staff talked up the gift shop at the train station, but it was pretty lame.

In Reno we stopped for twenty minutes, that was nice, just long enough to walk to the Reno arch and back.