Aboard Challenger No. 3985 ? When Steve Lee drives by, cattle stampede, deer run for their lives, fish jump from the water, children grin and gape and grown-ups wave.

It’s not the force of Lee’s personality that changes the world as he moves through it, but rather what he’s driving — a million-pound steam locomotive that shakes the ground as its 12 drive wheels churn along the rails.

Lee, of Cheyenne, Wyo., is the engineer who operates Challenger, locomotive No. 3985 of the Union Pacific Railroad, the largest steam locomotive still operating in the world.

In the cab with Lee is Lynn Nystrom, also a fully qualified engineer, who acts as fireman when the Challenger is on the rails. He watches the gauges, making sure the flames get enough fuel and are hot enough to produce the steam that drives the wheels.

“He’s making the steam,” Lee said, with a nod at Nystrom, “and I’m using it.”

Challenger passed in February through southwest Arkansas on its way to a stop at North Little Rock, where it was on display for a day as part of a nine-state monthlong excursion from Wyoming to Houston and back. The train returns in early June to Houston and will also run in late July between Denver and Cheyenne.

It also passed through Lawrence, Kan., on Jan. 14 on its way to the Super Bowl in Houston, and again on Feb. 10.

Wherever and whenever the train shows up, crowds gather to see the working relic of a bygone era. And where the train doesn’t stop, onlookers gather along the rail line, grinning and waving at the occupants of the locomotive’s cab as it speeds by.

“It made me think of the good old days,” said Don Walthall, 69, of Magnolia, Ark., who drove nearly an hour to Hope, Ark., last winter to see once again something that had been common during his youth.

“There used to be three or four trains (with steam locomotives) a day passing about a mile-and-a-half from my home,” he recalled.

A crowd-pleaser

Gary Johnson, director of the Hope Visitor Center and Museum, housed in the town’s historic train station, said the locomotive’s arrival was a big event for the community. Johnson is also helping Hope prepare for events related to the opening of the Clinton Presidential Library at Little Rock.

“I haven’t even had time to plan for the Clinton library stuff because for the last two months all we’ve done is prepare for this train coming,” he said.

Among the crowd of a thousand or more that gathered at Hope, hundreds of grade-school youngsters dismounted from yellow buses during the wait for Challenger’s arrival on a wintry day.

As the locomotive approached — belching steam and gray smoke from burning No. 5 fuel oil and issuing long blasts on its mournful whistle — the students stood on tiptoe to catch a glimpse of it in the distance.

“I can see it. I see its light!” a fourth-grader called out to her teacher.

As the huge engine, 122 feet long, inched to a stop, it drew a simple exclamation from a boy standing on the gravel railbed, 15 feet back from the tracks: “Wow!”

For nostalgia’s sake

Built in 1943 at the American Locomotive Co. in Schenectady, N.Y., Challenger was retired in 1962 and stored in a roundhouse at Cheyenne until 1975, when it became part of an outdoor display near that city’s depot. A group of Union Pacific employees started a restoration that took several years, getting the locomotive back in running order again in 1981.

The day before it arrived in Hope, the engine pulled seven cars behind it at speeds that reached 60 mph through the rolling countryside. Cattle in track-side pastures, accustomed to diesel locomotives, turned and ran from the chugging engine, and a group of four deer bolted and sped away, flag-tails flying. Horses shied and galloped off, and fish in water-filled sloughs along the track, apparently spooked by the vibration of the ground, cleared the surface of the water in agitated jumps.

Challenger is actually the name that was originally applied to a whole class of locomotives, 105 in all, built for the railroad. They were built to haul freight, not having enough speed to pull passenger trains.

“The only reason it was built was World War II,” Lee said. “There was a huge demand for transportation.”

No. 3985 is one of two steam locomotives still operated by Union Pacific, but both are strictly for show and nostalgia.