I live near Denver and search a few boxes of pennies a week. I have yet to find one. I even went up to Michigan and bought eight boxes hoping I would find one. Not a single one was found! I hope I don't have to resort to buying a nice example just to fill a slot in my book.
Thanks to Kurt for the Fed district map - puts this subject into a clear focus. If I want a large quantity of 's' mint coins, I order my circulated 90% bulk coins from west coast dealers, i.e. BGASC - JM Bullion ships from Nevada, so those lots have quite a few 's' mm coins as well. APMEX is in Oklahoma, so their bulk coins are predominantly 'd's - on eBay, check the location of the seller to predict the mintmarks - it's a geographic thing
Keep in mind, if either Mint has a supply issue, there can be cross-district shipments, but it's infrequent.
I'm sure in this day and age it's very infrequent. It's probably very rare that someone in one zone spends cents in another unless it's at the boundaries between each. How many people today actually carry change, let alone cents, when traveling. About the only time I use change today in a transaction is when driving through a fast food restaurant while traveling. I'll grab change out of my glove compartment and replace it with any other change.
Somebody once said, and I think it's almost true, the only remaining use case for the cent is sales tax.
Here on the west coast P-mint coins are rarely encountered in change (except dimes seem to be fairly common for some reason). When I travel to the East coast I try to stop at the local branch of my bank and get about $100 in rolls of coins (cents, nickel, dimes, quarters and if they have them halves). I usually fill all the P-mint holes in my albums from just these few rolls. I did this earlier this year when in York, PA. TSA didn't even bat an eye.
I live in Wisconsin just searched a box and found a roll of 2017P and a roll plus of 2017 D. P'S are not as plentiful as D's but we normally get a good mix.
Good Saturday to be in York this week. Pretty good coin auction. Turning in early again tomorrow night. Good doughnuts (gratis) at the auction, then a trip to Old Republic Distillery after the sale.
I make it a point to carry 4¢ in my pocket whenever I go shopping. My wife keeps coming up with pennies in very large numbers, then gives them to me to spend. She once had over $200 worth of them that I dutifully rolled up for her. I carry these 4¢ with me so that whatever the amount may be I can hand the cashier the correct number so that I can avoid getting any in my change. Right now I have a jar full of pennies that is somewhere near 400. I don't think I will be able to dispose of these faster than the jar will be refilled.
Seen 1 or 2 in circulation. 95% of the coins we get are D's. Dug up 1 or 2 metal detecting. A friend on the east coast mailed me a couple of MS examples.