And isn't there a shot in a preview of Spencer running inside a train car that looks similar to the one he's in...

He somehow sees Alex & stops the train.

Teonna can't get to the WY/MT border in time.

But Teonna's fellow Crow can. The Crow will probably find her, & once she tells them she's a Dutton &/or is trying to get to the ranch, they will help her because Jacob saved them early in Season 1 by giving them a lot of sheep when they were starving during the summer drought. Some of them will create an army to help Jacob. Or somehow she gets to the Sheridan, WY or Billings, MT station & Spencer sees her...

I love - based on Spencer in Amarillo - he will have almost the same trip as his parents/siblings trip to MT in 1883, but on a train. I'd love to see him stop at Yellowstone National Park & walk to the ranch using the same as Elsa & James.