After the railroad company stopped sending trains through that town, the tracks got overwhelmed with red rust, gray grass, black brush, and green trees.
The townspeople eventually purchased a a big whistle--a horn, actually--that sounded like a train because almost everyone missed that sound.
Now people take turns. One person goes down there one night a year and makes the horn make that sound. The horn is housed in a little shed, with ventilation to let the sound out.
Oh, now, if the train could only hear that sound, maybe the train would return. But--no, it's been gone too long. It's too far away. In the town's imagination, the train passes through an eternal red-rock desert, hauling its steel boxes of freight to the lip of an abyss, unloading.