dual citizenship, Schengen, and Eurail passes...

I do not have dual citizenship but I don't see why you couldn't do that. I know several people who use their passports interchangeably - the European passport when they travel to Europe and the US passport when they come here.

Well, what were you planning on showing then for your Eurail pass once those 90 days were up on your passport?
Just curious.

Railway staff have no business checking your legality status.
As per Eurail's own guidelines:
2. If you have a European passport and a non-European passport, use the passport/ID of the country you live in.

Agreed balso, railway staff have no business checking for any stamps in my passport.

Ms. Jo, your question is the reason for my asking to begin with.

Since posting, Rail Europe has suggested that I buy an Interrail pass instead, and use my European passport even though I am not a resident of Europe. Presumably the same railway staff will no more check on my residency than they will on my comings-and-goings through Europe....

they won't be looking at the pages at all, and they have no business to - they will be looking at the picture page with pictures and numbers, birthdate... matching up your name

Two points:
Using the EU passport to enter the EU and the US or Canadian passport to enter Canada or the US is the law, not just a preference.

Second, if the right to use the pass is based on residency, not nationality, it appears your primary residence is Montreal.

This is the situation that many French and other European ex-pats experience when returning to Europe for vacation. A similar situation occurs when leasing a car on a contract at reduced price reserved for non-résidents; in this situation the origin of the passport isn't important, but the primary residence is.

So yes, as overseas French citizens, we used to enter the Schengen with our EU passports, but we then rented or leased our cars using our American passports and driver's licenses at prices reserved for non-EU residents no matter their passports. We happened to have two passports, but even if we were only French, our overseas residency would give us the right to use our these contracts reserved for overseas residents. Our leases were often beyond 90 days. Remember that many ex-pats stay beyond 90 days on visitor visas, but under 182 days to avoid French taxation, and take advantage of rentals for non-résidents. As for the rail pass, I haven't heard of anyone using one in decades. Most of us living in Europe use discount cards.

Perhaps we can extrapolate from our experience and apply it to the rail pass, but without seeing your contract, all we can do is guess.

Thanks Bets for the anecdote. And again everyone else.

I'll use the best of both worlds where available to me (and yes, definitely only using one passport to leave Canada/enter the EU and the reverse.)

Interrail is NOT valid in the country where you "live", so if you have, say, a German passport and use that to get and Interrail pass, then it would not cover Germany. If I remember correctly and if it hasn't changed in 5 years, it would just cover 1 round trip from a chosen point of origin in Germany to the border of whatever country.

So in your case and given the rule I found, you should get a Eurail pass.
If a Eurail pass makes sense for your trip, that is ... If your trip includes France, Spain and Italy, I would steer clear of it!

Maybe to start with you should understand what an EU passport entitles you to when it comes to free movement:
- To go to an EU state in search of employment for up to three months and have that period extended to six months if it is reasonable to expect you are still likely to still find work
- Move to an EU state to take up employment
- To establish a business in an EU state for the purposes of self employment
- To move to an EU state for the purposes of family reunification
- To retire to an EU state provided you have sufficient funds to do so
- To obtain permanent residence status after five years in an EU state, if you have established economic viability
It grants you absolutely no rights as a tourist because these rules are to facilitate the single market not tourism.

In practice what that means is the EU citizens are not checked as a matter of curtsy not as a right. That means that if you can't show residency in the EU, they can send you back to the state on your passport. So while it might reduce the chances of you getting caught overstaying, it grants you no extra rights if the authorities decide to apply the rules to the letter.

Another point to keep in mind is that if you enter the EU on an EU passport you can't seek consular or similar services from your home country should you need them at a later stage. Likewise you may have issues with medical insurance if you needed treatment or make a claim since EU citizens claims are net of the cover provided by their EU health cards.

The price of Eurorail passes used by third country citizens and the price of Interrail tickets used by Europeans are not too dissimilar so not really sure if it would be worth effort.

Using the EU passport to enter the EU and the US or Canadian passport to enter Canada or the US is the law, not just a preference.

There is no such thing as an EU passport! There is EU citizenship, but you enter the EU as a citizen of a member state or the EEA/CH as the citizen of a state participating in those agreements. This is an important difference because at no point for instance are you entering or subject to the Schengen Rules. There are similar rules but they are not exactly the same.

Jim@ you used the short-cut terminology, EU passport, in the first sentence of your answer to Rene.