Mint Location And Areas Across The US

Here in Joisey we get mostly P mint stuff (Philly is just across the river). However, I have been noticing many D-mint Statehood and National Parks Quarters lately (almost disproportional, it seems). Can't explain why, though. I have to go to Vegas in October for a wedding, and I presume that almost everything will be D, although I'll bet (wink) that there will also be many P's out there, due to the gambling industry, even though I believe that slot machines no longer take coins (DARN!). I'm missing a few D JFKs, so perhaps I'll try to get a few rolls of halves while I am out there.