St. Goar location to explore Rhine and Mosel?

Yes, you can do that - but Trier itself requires a fairly full day. Suggest you stay over if you plan to go that far, or situate yourself on the Mosel mid-way between Trier and the Rhine instead. Cochem is a very attractive town with the best choice of eateries and things to do; Bullay is much smaller but scenically located and very convenient. Zell might work too.

We stayed in Bacharach, just down the river from St. Goar. When we went to Trier, we just took the train, even though we had a rental car. It was just much eaiser. FYI, we had to change trains in Koblenz, but that was no problem.

Id say Chocem may have a bit more choices - esp with car - but Bacharach may be just fine if its not too crowded. Either will get you to all the best parts of the Mosel and Rhine. The Mosel has some great spots that may be easier with car - so id pick that one for more day trips to Trier, Eltz, Bernkastel etc. If you need to be closer to Mainz/Frankfurt or want to go east to Wurtzburg/ROthenburg/Nurenburg - stay on the rhine side to save time those days!

We stayed in Bacharach and spent an entire day on the mosel returning at night to Bacharach.WE had plenty of time to visit Burg Eltz Castle(dont miss it).

I was in both St. Goar and Cochem last week. I visited Trier last year. I do not quite understand what you mean by exploring "both the Rhine and Mosel." Of course there is a lot to see. But you are not going to see it all in 3 days. I would rather spend time totally enjoying a few places than trying to see it all. A Rhine cruise takes a good half a day. Trier could take a whole day, at least. Exploring a castle takes a half a day if you count the time to and from, plus lunch. And don't forget the wine.

Just got home from there. I stayed on the Mosel and drove to St Goar for a day trip cruise to Bacharach and return. You could do the same in reverse. However, I stayed in a 3-room suite (FeWo) in Bruttig-Fankel - Familie Ernst, www.rolliholiday.de - for 50 Euro a night. Don't know if you can do that in St Goar. Good day trip cruise on Mosel is Bernkastel to Traben-Trarbach and return. Also, Cochem to Beilstein and return. I spent a week, but 3 days is better than nothing. See my post under Accessible Europe for details. Have fun.

Thanks for all the great advice. I wasn't thinking of exploring the entire Rhine but I guess I wasn't very specific! I was thinking perhaps a two to three hour cruise on the Rhine, visiting Baccharach, Burg Eltz on the Mosel and Trier and then other wandering along the way. But perhaps I am trying to cram too much in and should leave Trier for another time?After 3 days in this area we plan on two nights in Rothenburg, one or two in Fussen and then a week in Austria. Would St. Goar be a good location in light of this new information? Thanks!

If you were to just explore the Rhine, St. Goar is as good a spot as any. For the Mosel, it would make sense to spend at least a night along the Mosel, then move onto the Rhine or reverse. No sense backtracking back and forth between the two.