There I was, in the middle of the Rocky Mountains, looking down at the Colorado River. Animal tracks in the snow made a dotted line beside the water. But where, I wondered, were the bighorn sheep? The black bears? I pressed my nose to the glass and followed the tracks carefully, expecting — any second now — to see wildlife.

I was in my 40th hour aboard Amtrak, nearly 2,000 miles into a 3,218-mile cross-country adventure. I’d packed five books, my laptop, several movies and hours of music, figuring that I’d have plenty of time to kill. But I hadn’t unpacked any of it. Instead, I was so enthralled by the landscape that I’d forgotten I was supposed to be bored. And at this moment, I was convinced that if I focused with all my might, I would spot an animal.

Just then, the cafe car attendant yelled up from down below: “Other side!” As he sprinted up the stairs, a couple of us hurled ourselves to the right side of the car. “Did you see the elk?” he asked breathlessly.

By that point, the elk were far behind us. I returned to my seat and resolved to enjoy the view, with or without giant creature sightings. But before long, the animal prints had lured my gaze back to the snow deep in the canyon, on the bank of the river.

This wasn’t my first time in the middle of the Rockies. In the previous five years, I’d crossed the country four times by car with my beagle, Darwin. But as I approached the one-year anniversary of her death, I sought a new mode of transportation and adventure.

From my house on Capitol Hill, I heard the early-morning whistles of trains approaching Union Station. My retired neighbor had told me about Amtrak’s long-distance routes. There are 15 of them, covering 18,500 miles, and most existed in some form before Amtrak was established in 1971. For generations, these long-haul trains have played an important role in transportation between rural communities.

My neighbor regularly travels all the way to Seattle on the Empire Builder. And the more I heard from her, the more I felt drawn to a journey by rail. So I booked a small room on the Capitol Limited from Washington to Chicago, and then on the California Zephyr from Chicago to San Francisco.

Before the trip, I had moments of doubt; I worried about boredom, stiffness and insomnia. But those worries were trumped by my faith in the Amtrak brochure, which suggests that there’s still some romance to train travel: “From orderly farms in the heartland to spectacular views of the mountains — the scenes are unforgettable.” Americana aside, who can forget the train scene in “North by Northwest,” in which Cary Grant’s dining car companion says seductively, “It’s going to be a long night. And I don’t particularly like the book I’ve started. You know what I mean?”

On a Saturday afternoon at Union Station, sleeping-car passengers were ushered to the track, and I found my room in the double-decker Superliner. The freedom to explore the train was intoxicating. I walked through the sleeping cars and the dining car, downstairs to the cafe car. As we rolled through the Maryland suburbs, I sat at a table near the snack bar and was soon joined by a man with a sun-weathered face who introduced himself as Rocky.

“Where are you going?” he asked, working on his second bloody mary.

“San Francisco,” I said, nearly bouncing in my seat with excitement.

Rocky raised his eyebrows. “Goll-ee,” he said.

I made a dinner reservation, and when the time came, the maitre d’ announced, “Ladies and gentlemen, please make your way to the dining car. Keep in mind it’s community seating. You will make a friend.”

I was seated with a Colorado-bound mustached musician wearing a bowler hat and an orange bandanna around his neck. Train etiquette seemed to involve asking strangers where they were headed and why they’d chosen the train. Some people were fed up with flying, others loved the slower pace, and some were trying it for the first time — and were surprised by how many hours they could spend looking out the window. I found that buying a train ticket bought far more than a ride; it bought time to talk, listen, look and think — and time to ask questions you’d never ask otherwise.

“So what makes your mustache curl up?” I asked the musician.

“Hair glue,” he said, explaining that without it, the mustache would curl down, giving him a completely different look. “Then it’s less evil villain and more gold prospector.”

From the dining car, I peered through the window into a cozy-looking second-floor room in a house near the tracks, where a boy was jumping on the bed. “I feel like we’re watching a movie,” I said.

The musician said that his favorite part of train travel was passing through towns. “If you take away all the cars, it’s like you’ve gone back in time. Some of these places haven’t changed much.”

Back in my room, I surveyed the space: two facing chairs (which my sleeping car attendant, Art, converted to bunk beds), a fold-out table, a closet as wide as one shoe, a narrow mirror, electrical outlets, a temperature knob, towels and bottled water. There was barely room enough to pull a shirt over my head.

Sleep came easily — the train is surprisingly smooth and quiet. I woke up only when we stopped to refuel around midnight, in Pittsburgh. As we left the station, I sat up in bed, looking out my window at the glittering city lights. The route followed the Ohio River for miles, and the urban landscape turned rural. I felt as if I were seeing the world from backstage, a view reserved for those who dare to get out of their cars. I even marveled as we passed eastbound freight trains. I wondered where they were going, what they were carrying and which train was moving faster. Then I found myself reminded of those insufferable high-school math problems, with trains leaving at different times and traveling at different speeds. With that, I crawled back under the covers and fell fast asleep.

Early the next morning, Art slid the New York Times under my door. After breakfast, he told me that he’d been with Amtrak for 17 years. I asked whether he’d been on the California Zephyr.

“Pictures and postcards don’t do it no justice,” he replied. “You gotta see it for yourself.”

The Greek god Zephyrus is the god of the west wind, and the more I heard about the California Zephyr route, the more I was prepared to be blown away. I boarded train No. 5 at Chicago’s Union Station.

“I am your attendant. I go all the way to California,” announced a voice on the sleeping car loudspeaker. “My name is Will, Willy or William. Not Bill, Billy or Billiam. I will not answer to a B.”

That afternoon, we passed through Illinois and Iowa. “Good time to read,” the conductor noted.

But I spent most of that day in a swivel chair in the observation car, facing a picture window. I met a middle-aged aerospace consultant fond of memorizing almanacs. He said that he was taking a break from work to live like a retiree while he was still young enough to enjoy it. A down-on-his luck Army Reservist, home from four tours in Iraq, was heading home to California after a trucking job hadn’t panned out. And a recent master’s graduate named Yasushi was heading west before flying home to Japan. He told me, in broken English, to call him “Sushi.”

We crossed the Mississippi and Missouri rivers before stopping in Omaha, where a new conductor and engineer boarded. In the morning, we pulled into Denver well before our scheduled arrival, which gave us plenty of time for fresh air and leg-stretching on the platform. I walked with Sushi, who was wearing Hanshin Tigers baseball flip-flops, toward the front of the train to look at the back of Coors Field. “Rockies!” Sushi announced, pointing at the ballpark.

The anticipation was building. Several of us secured seats in the glass-ceilinged observation car for what promised to be the most beautiful stretch of perhaps any Amtrak route — from Denver to Glenwood Springs, Colo. There were retirees sitting quietly, skiers talking sports, young people playing cards and a couple of families with toddlers. We all had our cameras ready.

Within minutes of leaving Denver, we were winding our way into the Rocky Mountains, passing through a couple of dozen small tunnels. As we exited the 6.2-mile-long Moffat Tunnel, we hit Winter Park, whose ski slopes — and skiers — came right up alongside the track. We had climbed nearly 4,000 feet in just over 50 miles.

For the next couple of hours, heading toward Gore and Glenwood canyons, I lost track of time. There was such excitement in the car: gasping at the panorama, trying to absorb the view on both sides and searching for well-camouflaged animals.

Mostly, we saw rock formations so grand and at such proximity that one of the card players exclaimed, “It’s like Disney World!” and an older passenger was reminded of a Louis L’Amour book. At times, the tracks hugged the edge of a cliff. Below, the river snaked and chunks of ice interrupted the flow of whitewater. The views were exquisite — like nothing I’d ever seen in these mountains on foot, in a kayak or by car. At one point, Sushi looked at me, pumped his fist and cried, “Rockies!”

In the middle of the night, the conductor woke me. I was stopping for a few days in Elko, Nev., for the National Cowboy Poetry Gathering. The conductor had called a taxi for me, so a car was waiting when I walked off the platform at 3:40 a.m. in this gold mining and ranching town. A man in a cowboy hat sat behind the wheel.

I caught the same train several days later at 3 a.m., under a full moon. This time I rode in coach for the 14-hour trip to San Francisco. The amount of space between rows on these trains makes a joke of airplane legroom; I didn’t even notice when the seat in front of me was reclined.

After breakfast, I again planted myself in the observation car. I met a San Francisco firefighter and a Berkeley, Calif., photographer, and we bonded over motorcycles, solo travel and month-long birthday celebrations.

From Reno, Nev., to Sacramento, one of the most historic stretches, volunteers from the California State Railroad Museum hopped on board and talked about the first train robbery, epic fires and snowstorms, and the building of the transcontinental railroad.

We climbed into the Sierra Nevada and followed the Truckee River. I saw snow-capped mountains reflected in Donner Lake and small communities where townsfolk shot pictures of the train. We reached an elevation of 6,939 feet before the scenery started changing. Soon we’d hit Roseville, Calif., home of one of the nation’s largest auto malls.

The train arrived nearly an hour early in Emeryville, near the San Francisco-Oakland Bay Bridge. The track ends here, but an Amtrak bus takes passengers into the city — a rather anticlimactic ending to the Zephyr’s journey of 2,438 miles.

Of course, Amtrak has its shortcomings. The bathrooms are cramped, the sinks are the size of melons, and water tends to spray everywhere but on your hands. Some routes use china and glass on the white tablecloths, while others stick with plastic and paper. The food, for the price, was largely disappointing (overcooked vegetables, so-so fish), especially knowing that the chef is able to pick up fresh ingredients at stations along the way. And although my trains were generally on time or early, that’s not always the case. Railroad companies such as CSX and Union Pacific own the tracks, so Amtrak — a guest on the rails — is at the mercy of the freight trains’ schedules and mishaps.

The experience seemed to be a blend of family car travel, scenic rail tour and summer camp — complete with star-gazing and walking around in PJs. The conductor reminds you to wear shoes if you get up in the middle of the night “so you don’t hurt your tootsies.” And you’re never far from a meal.

Once in a while I came across an Amtrak employee who was simply clocking in. But it was clear that most of them felt as though they had the best jobs in the world.

I visited friends and family in California, making my way to the southern part of the state. The night before I left, my grandmother asked me to speak to the women’s group in her assisted living facility. As I told them about my journey, a few faces lit up. Bea, a 96-year-old with white hair and tiny spectacles, said that she’d taken the Zephyr decades ago. “There were these great big windows,” she said, lifting her arms above her head to illustrate the view. “You really saw the country.”

The next morning, I drove out of the Mojave Desert toward Los Angeles International Airport. I passed a freight train running parallel to the freeway, and I realized that this must be Amtrak’s Sunset Limited route. My rental car sped me toward the airport, and the jet would later zip me home. But for a few moments, as I stole glances at the train, I forgot that I was on asphalt. All I could think about was being back on the rails.

Kaplan is a freelance writer in Washington. Her Web site is www.melaniedgkaplan.com.