Train from Chambonix-Mont Blanc to Paris CD

What sort of advice ? Train from Chamonix is the westbound Mont Blanc Express to Saint Gervais - LeFayet . From there , a TER train to Bellegarde sur Valserine , then change to the TGV ( high speed train ) to Paris . 5:30 hours . From Paris , RER B to CDG , about forty minutes

Thank you for response😀 I’m only finding two 6 AM trains, perhaps it is too early to book

Where are you looking ? And when are you going ? I can give you a better answer with that information .

I did a quick look for a random date in mid-March. and got the following:

Chamonix-Mont-Blanc 07:15, 2 changes, Paris Gare de Lyon 12:49
Chamonix-Mont-Blanc 09:15, 2 changes, Paris Gare de Lyon 14:52
Chamonix-Mont-Blanc 10:54, 3 changes, Paris Gare de Lyon 17:49
Chamonix-Mont-Blanc 12:15, 2 changes, Paris Gare de Lyon 18:45
Chamonix-Mont-Blanc 15:15, 2 changes, Paris Gare de Lyon 20:49
Chamonix-Mont-Blanc 15:50, 1 change, Paris Gare de Lyon 21:49
Chamonix-Mont-Blanc 17:15 , 2 changes, Paris Gare de Lyon 22:49

From Gare de Lyon to Charles de Gaulle airport (I guess that's what you mean by "CD"), is just the RER. That's a frequent commuter train, just get the first one that turns up.

Where are you looking (which website), and for what date?

We are traveling this route on May 15 and want to make 1st class reservations as soon as possible. We have Eurail passes

You will need to go to SNCF ( French national railways ) to book reservations for the TGV leg. The seating allowance is restricted for pass holders - one good reason not to use passes in this day and age ) The two TER legs are open seating , no reservations required or available .

I have not previously found it easy to make passholder reservations through SNCF. For simplicity, I'd make them through the agent who sold you the pass, such as our link. You can only reserve the TGV portion of the trip, so only request that section. Passholder reservations are no longer artificially limited on domestic TGV but the price does go up if the train is busy.