For all Amtrak train rides between September 18 and November 18, 2017 you will earn double points! This is for any route, no exclusions!
Typically you earn 2 points per $1 spent on Amtrak travel, so with this promotion you’ll earn 4 points per $1. You must register for this promotion. The terms do not state whether registration must be done by travel date or not, but I’d suggest just doing it now.