I've dug several 1916 Mercury dimes over the years, and always hope when I flip them over the check the mint mark that it'll have the coveted Denver key date mint mark. Finally dug one. Ironically when I dig it, I didn't even look at the date, dropped it into my finds pouch and when I got home I was checking my finds and then saw the date on the Mercury dime. OK another 1916, I muttered to myself as I flipped it over to check the mint mark...."Come on, be a Denver mint mark!" and low and behold it was!!