Thank you much for the suggestion.  I will do that here and again. (BTW:  There is no such button anywhere above, so I may need to do more 'responses' before I get to post).  So here we go.....
I have purchased acreage to build a final home.  On my very clayey till, level site near a stand of trees, the previous owner had dug two 13' diameter pits, each 10' deep.  I don't know why.  Apparently he did not get a permit to do what he wanted, and he then refilled in both pits with the same hard clayey till, he dug out - except for a pile of boulders and stones left in a pile on the side.  My QUESTION IS... both piles have settled an inch or two from the level of grade - How long will these pits need to completely settle so I can build on them?  Is there a way to speed up that settling?  Thanks.