The men knew that beyond that break ran the steel rails that connected the town with Red Rock, their destination.

But it was plain to them that the rails must make a gigantic curve somewhere in the invisible distance, or that they ran straight into a range of low mountains that fringed the northern edge of the mesa.
Lawler enlightened the men at the camp fire that night.
"The railroad runs almost straight from Willets," he said.

"There's a tunnel through one of the mountains, and other tunnels east of it.

And there's a mountain gorge with plenty of water in it, where the railroad runs on a shelving level blasted out of the wall.

The mountains form a barrier that keeps Willets and the Wolf River section blocked in that direction.