One address, one number, one direction
Write in, or speak to a travel agent in Washington DC before you reserve anything
Two ways in, and they run at different speeds. The form and the email address take anything at any hour and are answered inside one working day. The telephone reaches a person during working hours.
Reserve this with the officeNothing is charged here. The form stays open at any hour and a person writes back inside one working day.
The telephone runs one way
The number is answered here during working hours and a message left outside them is picked up on the next working day. This office does not telephone travellers who have not asked to be telephoned, does not send text messages, and runs no automatic dialling of any kind. If you would rather be called than written to, say so and give a window; otherwise everything comes back in writing.
Two addresses, kept apart on purpose
The form and the reservations address go to the same place and are read by the same person. The postal address at the foot of the page is the registered office and is where paper reaches this business, not where a request should go. Sending a booking question by post will get an answer, but slowly, and there is no advantage in it.
What to put in a first note
The weeks that would genuinely work, how many of you there are, and whether you are asking about one segment or a whole line. That is enough for a useful first answer. Anything else that changes the shape of the trip is worth adding at this stage rather than later: a knee that will not take a long descent, a wish not to move at night, a fixed date somebody else has set.
Reserve one segment, or a whole line
This form is open at any hour, and whatever reaches it is read by a person who answers inside one working day. Nothing you send commits you, and no figure is charged at this end at any point.