Yes, it is made in USA. An employee from Proco posts here sometimes and actually discussed the YDR in a Rat thread mentioning this (plus, I had one and it does come with "Made in USA" on it).
It's a good Rat sounding pedal, but I think I like the older Rats better (didn't do a head to head though).
I know RAT2 is made in China now but I cannot find any info about YDR.
I have spoken with Proco and they have no plans to have the YDR manufactured overseas. It's a very good RAT and it's true bypass and is built like a tank.
Thanks - I am asking because I would like to install Allums mod in in it and Monte says on his website that Chinese RATs do not take mods well.
he also says on his web site that he does mods on the you dirty rat specifically. and indicates that the YDR is still US made.