Just started playing today.
I created track from Yuma Mills, Ltd. to Las Vegas. I built the annex. When I went to buy the train, it wouldn't let me create a route between the two. I had double track in Las Vegas.
This has happened in two other scenarios.
What am I doing wrong?
Thanks in advance.

The track has to run to all the stations you want to connect. This mostly happens when double tracking without a switch there. Also the game is not like RL trains, they will not back to a switch just outside the station and change tracks. Next be sure that switch track is connected. This results in black dots at stations you can't reach. Other problems occur when going to multiple stations where the last drop leaves the train where it can't reach the starting station.