Riddle, Owyhee County, Idaho Genealogy
The Gem State Rural's 1918-19 Farm Directory of Owyhee County Idaho and Malheur County, Oregon is available online. It lists landowners by town, including those owning land in these two counties, but residing elsewhere. The amount of acreage owned, the location of the land, and a list of crops raised on each farm is also included. The resident land owners of the Riddle area are listed on pages 147-148.
Wikipedia page for Riddle.