D
- Des Moines County, Iowa: Des Moines is named for the Des Moines River.
- Deschutes County, Oregon: Deschutes is named for the Deschutes River.
- Dolores County, Colorado: Dolores is named for the Dolores River, originally Rio de Nuestra Senora de los Dolores, or, in English, "River of our Lady of Sorrows".
- DuPage County, Illinois is named after the DuPage River.
Read more about this topic: List Of U.S. Counties Named After Rivers