La Plata, sometimes spelled La Platta, was the first county seat of Deaf Smith County. In the election separating Deaf Smith County from Oldham County on Oct. 3, 1890, Grenada was chosen as the county seat, and the name was changed to La Plata. All buildings from the townsite at the center of this section were later moved to Hereford when the county seat was moved there in 1898.