Is This Greeting Exclusive to the Northwest?

I was in New York not too long ago when someone pointed out a phrase he heard me say upon my arrival that is one he only heard from his extended family who happen to be from Spokane. Got me thinking, maybe it's just a northwest thing?

The phrase? Thank you, much!

When a server delivers food to my table: "Thank you, much!"
When I get change back: "Thank you, much!"
When someone holds open the door for me: "Thank you, much!"

Do you know others who say this? Are they regional? I don't even remembered when I started to say this, I just kind of did and kept it up this whole time.

Thank you, much!