Swiss Pass

You have to buy a ticket separate in Martigny where you will change for the Mont Blanc Express on the way to Chamonix. The Swiss Travel Pass does not cover that part. There is a machine right there to buy a ticket and someone will check it. That route is very scenic.

A few things to consider - There are two ways to do this trip , depending on your time frame , the length of your pass in days and your itinerary . The route AI lists above takes you from Geneva east via Montreux across the north shore of the lake and south to Martigny . At Martigny you buy a ticket from the border station ( Chatelard le Frontiere ) to Chamonix . The trip on the Mont Blanc Express starting in Martigny takes you high up over the Trient Gorge with striking scenery , a ride not to be missed . ( sit on the left side of the train in the direction of travel for the view ) There is another option - If you do the trip this way it will cost a day of your pass. To save that day and still do this route ( in reverse ) Take the new CEVA route from Geneva Cornavin ( French TER trains) to St Gervais - LeFayet and switch to the Mont Blanc Express there , headed east to Chamonix . When you leave Chamonix heading east to Martigny you will only need the ticket to the Swiss border , then your pass takes over to Zurich . You still get to ride that beautiful section ,and the trip from Geneva to Chamonix is somewhat shorter .

The CEVA trains are best known as The Leman Express routes, I think there are about six or so . https://www.lemanexpress.ch/fr/

Note: The Mont Blanc Express line is undergoing maintenance work until 13 NOV 22. Therefore, train services are limited or replaced by buses.