Wild Horse Lake is a playa lake located in Texas County, Oklahoma. The lake was the location of the infamous Hay Meadow Massacre (July 1888) in which one faction in the county seat fight in Stevens County, Kansas, killed four members of the opposing faction. Since the killings took place in what was then No Man's Land, no court had jurisdiction over the crime. The lake was also the subject of Oklahoma case law in reference to water appropriations—Depuy V.