An estray notice in the Thursday, December 4th 1766 edition of Rind's Virginia Gazette placed by Shem Cook. (www.newspapers.com)
A search of estray laws at Google Books yielded several books which cover colonial and early American law. I found one about the areas in which many of my ancestors lived but I'm sure there are others there or at the other online books sites. Try a search for one and include the name of the area in which your ancestors lived.
From Google Books
Laws of the State of Tennessee: Including Those of North Carolina Now in Force in this State. From the Year 1715 to the Year 1820, Inclusive, Volume 1
The Revised Code of the Laws of Virginia: Being a Collection of All Such Acts of the General Assembly, of a Public and Permanent Nature as are Now in Force; with a General Index. To which are Prefixed, the Constitution of the United States; the Declaration of Rights; and the Constitution of Virginia, Volume 1
