What is the best site to look at train schedules within Switzerland? I am looking at train travel from Chamonix to Grindelwald in September. I know you can only get a general idea this far out but wanted to start planning. Is Rome2Rio a reliable site or is there a better one?
Definitely use SBB, the Swiss train app/website.
Rome2Rio is an emergency "I have no idea" site. In this case, use SBB, since they run the trains, at least after Vallorcine.
It will look something like this. Chamonix Mont Blanc>Vallorcine>Martigny>Visp>Spiez>Interlaken Ost>Grindelwald.
Thank you!
If you want to see some wacky answers just for fun and entertainment give Rome2Rio a spin.
Otherwise, in the words of Monty Python, "Run away, run away, Run away, run away, run away. Run away, run away."
Use the official SBB app and/or websites - they run the trains, and lots of people here (not me) know all about the Chamonix connections. A part of the area I've never visited - I know about many areas of Switzerland not in the French language area and a fair amount about the trains.
You don't need to worry now about getting between those two cities as they are popular cities with several options. There are a lot of things to see in between were you may want to stop and see along the way. Google maps can be used to get ideas (put in Sept date), but SBB is your primary tool for the tickets. Enjoy your trip. I like really liked both locations.