One Meel-Yon Dollars

The donations box at the Check-Out Desk usually has a "$1million dollar bill" in it that some wiseacre refreshes every time the box gets emptied. Amazingly, almost every day someone will see it and ask if it's real.
As far as I can determine, suspecting that it might be real commits you to believing (at least) these three theses:
(1) The US government mints or has minted a $1,000,000 note.
(2) Someone who wanted to donate $1,000,000 to the Missoula Public Library would do so anonymously and in cash.
(3) Someone who wanted to donate $1,000,000 to the Missoula Public Library would just put it out there in the open where everyone can ogle it.

No offense, but the only one of these that is even remotely plausible is (1) (remotely plausible, but still false). Furthermore, I consider myself a pretty honest guy, but I'm sure that I'm not alone amongst library staff in that I would probably seriously consider breaking that puppy out of the box and hieing on out of town with it, were it real.

I mean, a million dollars just lying there? For real?

Please.