I used to borrow a machine from a friend in the UP of Michigan. I worked over old logging camps, cabin sites, portages, creekbeds below rapids, anywhere else that showed the signs of unusual human activity.
Found numerous axe heads, a copper arrowhead, tin cups, knives, some very old rifle cartridges for the old blackpowder rounds, watches, rings/mdse jewelry (very little precious metal stuff though), rifle and pistol bullets, horseshoes, cut and forged nails, a british pattern musket lock, a copper kettle, and numerous modern coins.
My favorite haunt was a ghost town out in the woods with a couple of rotted down log buildings at the end of a washed out railroad grade. It had been operated as a trading post since the early 1600's, logging camp circa 1850 cutting large white pine timbers for ship building, a later logging camp for the big boom through the early 1900s and a backwoods speakeazy, whorehouse and whiskey smugglers hideout and depot through the 20's. Don't even ask, I'm not giving up the location. I'm one of 2 people who know both the history and the location of this place. Found silver and copper coins of 17th century french, british, german and spanish origin, 18th century silver from France, britain, Quebec and early colonies, 19th century copper, silver and one gold coin across the board, found a stash of 196 1900-1922 dated silver dollars, an early 1900's $10 gold and buckets of buffalo nickels, most with bullet holes in them all near the base of a rotten stump (I'm guessing somebody liked to tack them up on a tree for target practice). Found a large quantity of 38 super, .45 acp and 35 rem brass at this site.
Need to invest in a more modern metal detector and make another trip there someday. Wish I still had the silver I dug up there. Got broke and had to sell it back when the stuff was cheap. Local rumor has it there's a stash of weapons and gold coins up there still that was hidden in a hollow tree in the late 20's when the Feds busted up the place.