Interlaken to Fussen

That is pretty much it. Not very convenient. If you are brave you can go via the Sustenpass for a more scenic detour.

Kaitlyn, Funny you posted this, I was just searching the same route and have been running into similar difficulties. Train travel is 6-8 hours depending on when you leave, with 3-5 changes. If you plan on seeing Neuschwanstein the same day you would have to leave by 7AM I would guess. Otherwise, you could take a train from InterLaken to Lindau Germany (3-4 hours). Then rent a car drive from Lindau to Fussen (1.5 to 2 hours) to avoid the drop off in another country car rental fee. It seems like there are faster train connections through Luzern (4 hours total to Fussen). Alternatively, you could drive the scenic route, don't know how long that would take. I would check the d bahn or swiss rail websites for specifics on railways. Personally I always favor d bahn (German rail website). Please let me know if you find a favorable route.

Yes, I was going to suggest you look at the German Rail (Bahn) website. There are other routes, although probably not faster or more scenic. And the best fares are probably going from Zürich to Buchloe on one of the ECs. You can go west to Basel, down the Rhein to Karlsruhe, then across Germany through Augsburg. Alternatively, you can go basically north and cross the border at the west end of Bodensee, then through the Schwäbisch Jura to Stuttgart and from there to Füssen. As for renting a car in Lindau, you are likely to spend as much time picking up the rental as you would save driving vs the train.

Kaitlin, That trip will take a minimum of about 7.5 hours, so it's going to be a full travel day. In the same situation, I'd use the departure from Interlaken Ost at 08:00, arriving Füssen at 16:56 (time 8H:56M, 2 changes at Karlsruhe and Augsburg, reservations compulsory on one leg). While it's a bit longer than some of the other trains, having only two changes makes it a bit easier (IMO). Have a look at the German Rail website for a look at the other options. Happy travels!

"As for renting a car in Lindau, you are likely to spend as much time picking up the rental as you would save driving vs the train." Umm... no. I've driven this route several times. It's taken me as long as 90 minutes and as little as 75. The quickest link via public transportation is 2:30, with one transfer. It doesn't take a full hour to rent a car.