Altus to Forgan
This MKT "Panhandle Line" served primarily agricultural areas, was largely abandoned in the 1970s. It connected with The Beaver, Meade and Englewood Railroad at Forgan.
Thanks to Mike Palmer for contributing information.
If you want to learn about this part of the Katy Railroad, you need to buy a book called
Katy Northwest: The Story of a Branch Line Railroad By Donovan L. Hofsommer
Best dirt track railroad around