ohio cemetery

On property I have permission to metal detect I have recently found out there was an old cemetery, most maps I have found do not show the cemetery and the 2 I have found do not give a very detailed location, all i can say for sure is I can probably narrow it down to to a hundred yard area
  I have been through this field several times while deer hunting (havent had my detector out there yet) and have not ran across any signs showing an old cemetery. One map from the 1880's shows a house very close to the cemetery and the cemetery only shows up on a 1960 something county map and a more recent (maybe 5 year old) county map.

  I am wanting to detect there this weekend and looking for any pointers on better locating the cemetery and hopefully the old house. anyone have any suggestions on why the cemetery is no longer visible? I am sure probably a very small cemetery but would think there would be some signs. maybe plowed over years ago? dirt eroded over the grave markers?
  In the same field but  probably a hundred and fifty yards west of where i would roughly put the cemetery and house there is a lot of very large rectangular rock at the edge of the woods thrown on a pile, when I came across them deer hunting earlier this month I found it to be strange. also in the field 30 yards out from the woods. close to where the big rectangular rocks are, we found much smaller square rocks in one small are maybe  10 feet apart and we found 4 of them all 4 very oddly rectangular, proably 20"x12"x6" which i would not think they are any kind of markers but maybe part of a house?
 also the rocks in the woods are probably 3'x2'x1"

  Any help would be appreciated and I will let everyone know if I find anything Saturday

We've got cemetery's dating to the late 1600's here and all the markers still have semi legable chislings on them, if they dont show signs of being chisled there probably not markers

They were Either KNocked Down & burried over Time, Or Even Removed, If you search the Area & you get a Concentration of metal, You should dig & Examine each Piece. I'm shure If You Locate something Cemetery related, you'll recognize it. (Iron Fencing, Grave Stones {some had Iron Pipes in them}, alot of glass {mason jars were used as flower vases}, ) do some searching, Let us know what you found. We'll be able to tell you if you hit the right spot. Don't dig more then a foot deep. GOOD LUCK ; Happy Hunting ; Jeff

have found several on old plantations that are just rocks with no markings or regular shape. found several on one that had a " S" on them. research told me this was how they marked slave graves

well thanks for the info everybody, I think I am going to start around where we found the rocks and work are way to where it looks like it is at on the map. I am supposed to be doing this tomorrow but not sure because still might be snow in the field but should be melted by then, we are supposed to have a heat wave tomorrow, mid 50's!

Might check Terraserver & see if an aerial view shows the spot. Spotz