Two of our girls made appearances in this movie, GP7s 1804 and 1810.  After leaving the Alaska Railroad, they were sold to Santa Clarita Railway and became movie stars with Steven Seagal in Under Siege 2.  These two locomotives were again sold, with 1810 going to Samuel's Industries in Milwaukie, OR and 1804 going to the Gold Coast Railroad Museum in Florida.

This information was provided courtesy of the VP of Sales for Colorado Railcar:

As you are aware, the Under Siege II train was assembled by Colorado Railcar.  All cars were former Southern Pacific gallery commuter coaches.  One of the better cars did serve for Transcisco in the ill fated San Francisco/Reno service.
 
The remainder of the cars were nothing more than shells.  All of the cars were hand painted using rollers and latex paint. The amount charged for the paint jobs was approx. $500.  The one car used in the close-up scenes was almost entirely fake.  Handrails and what looked to be metal was in reality, balsawood.  The fluting on the sides of a few cars was actually roofing material that was simply screwed on to the sides of the cars.
 
Upon completion of the movie the cars were returned to Ft. Lupton.  The center sills of two of the cars were used in the building of the Princess owned Midnight Sun Express.  A few of the center sills are still in Ft. Lupton.  The carbodies have long since been scrapped.  Some of the trucks have been reused and others are sitting in the storage yard.

Filmmakers pioneered a new technique that enabled them to film all the interior train scenes (practically all the film) in the studio. Tennis balls glued on the studio walls were used as reference points to allow computers to insert footage of Colorado scenery, even when the camera moved around.

During initial test runs for filming of the external scenes, sparks from the locomotives caused flash fires along the railroad. The locomotives had to be modified with spark arrestors before filming could begin.

The railroad passenger cars where built especially for the movie by Colorado Railcar Company and are still in existence today.

The scenic train shots were done at Glenwood Canyon in Glenwood Springs.  Through the years the Glenwood Springs area has served as the back drop for other such films as The Great K&A Train Robbery, Flashback, Messenger of Death and Tall Tale: The Unbelievable Adventure.

Steven Seagal plays the lead in "Under Siege Two: Dark Territory." He remarked, "We did hook up and hang off of mountains, and I guess anything could go wrong, something could break and you could fall. I did jump on a train and run down it while it was moving, and you could fall off there, and if you do you would probably get hurt if not die."

Of course Steven Seagal can be expected to do some of the dangerous stuff -- he's the hero. But what about the villain, actor Eric Bogosian, whose career up to now has mostly been one-man stage shows? He says, "Action movies, when they're filming them, they have to spend a lot of time thinking about the action. And they have to spend a lot of time making sure this stunt man doesn't get burned to a crisp, that this helicopter doesn't fall down, and so on."

And some of the supporting actors, like Morris Chestnut as Seagal's reluctant sidekick Bobby, and 16-year-old Katherine Heigl as Seagal's niece, find themselves doing things that they weren't expecting. For example, Heigl says, "In the sound stage I had to climb up a rope ladder to get to the helicopter, and I was climbing and climbing and doing the whole bit, and they say OK cut, and I stop -- and I look and realize I've gone almost into the rafters which have gotta be three stories high, and I'm terrified of heights. It was hard to get down."

Morris Chestnut has his own tale to tell. "We were in Colorado, and I remember there was this train track. Ten feet from the train track was this cliff that went down a hundred, two hundred feet, and right on the other side was this mountain. So you really couldn't go anywhere. The wind was blowing ferociously. That's when I started crying for my mama."