PROMONTORY -- The May 10 celebration of the joining of the Transcontinental Railroad is as predicable as a sunrise, but every year, people find something to amaze them.
Thursday was the 143rd anniversary.
As always, the National Park Service and volunteers at the Golden Spike National Historic Site brought out the polished replicas of the Jupiter and No. 119 steam engines, posed them for the famous picture where they meet nose to nose and then let them sit, hissing and chuffing, glinting in the sun.
Several hundred rail fans mingled, admiring the massive machines and peppering the crew with questions.
The crew members love to answer. They're rail fanatics, too. Most work there for free and study this stuff for fun.
Ron Wilson, engineer on the Jupiter, said the May 10 anniversary is the single best chance the public has to get a close look at the piece of history on display at Golden Spike National Historic Site.
A man walked up. "So is anything on these engines original?" he said, pointing at the Jupiter.
No, Wilson explained. The engines used in 1869 were junked a century ago. The two now at the site are completely accurate reproductions built in 1979. They are exact working replicas, down to the same forge marks.
Wilson wears an old-fashioned vest and other clothing to look the part, complete with gold pocketwatch chain threaded through a buttonhole. A small clutch of Chinese coins dangles from the chain, for luck.
Like most Golden Spike engine workers, he digs out his best vintage railroad watch for May 10. His is a worn, but shining, gold Illinois Watch Co. piece that ticks along sedately.
But that watch is only used on May 10, he said. Other days, he brings a junker.
"There's a reason," he said, and told of an earlier engineer who wore a good watch while shoveling coal into the engine's firebox.
Wilson mimed wielding a shovel in the narrow cab and showed how a wayward thumb swung close to the vest could catch the watch chain, flipping the watch forward.
"The watch goes right into the middle of the flames," he said, then shook his head and added, "Ouch! There's nothing you can do. You stand there and watch it melt."
A woman pointed to the small American flags fluttering from the engine.
"Is there significance to the arrangement of the stars?" she said, noting the stars on the flags are in a circular pattern, with one large star in the center.
No, Wilson said. In 1869, there were no fixed rules on the pattern of the then-37-star flag.
"There was some research done, and this arrangement was on the flags they used here on May 10."
Over at the 119, engineer Richard Carroll explained the elaborate gold-and-red filigree decorations of his engine.
Crew members declined to guess how many gallons of brass polish they use getting their babies ready for
May 10, but "several" seemed about right.
A visitor asked if these engines were specially decorated for May 10 or if historic engines always looked so pretty.
Always, Carroll said.
The 119 was a working engine in Ogden, brought to Promontory at the last moment, "but this is the way it looked in 1869."
"The crews were assigned to each engine, and they took pride," keeping their charges clean and polished.
"As time went on, the accountants took over the railroads, they needed profits, they transferred the crews around, and that pride went away."
The same visitor asked if the engines really operate on steam, at which point a puff of steam chuffed out from the 119, spraying his legs.
"I guess that answers that question," he said, smiling.
If any kid at the festivities was sure to be having a good time, it was Nathan Paskett, 8, of Ogden, who was there with his dad, Jon.
Jon Paskett said Nathan is all about trains.
"This is his dream," he told a park employee.
"I ask him, 'Do you want to do what I do?' and he says, 'No, I'm going to drive a train.' "
Dad has taken Nathan to Union Station in Ogden multiple times and catches Thomas the Tank Engine every time it's in the area.
Of course, Nathan has lots of model trains at home.
But the May 10 Golden Spike celebration of the event that shaped modern railroading in the United States is the peak.
"We heard this was going on, I got his teacher's permission, and we're out here," Jon Paskett said. "We're having a daddy-son day."