The Granger Clay Pit fossil fish fauna is from the Middle Miocene Ellensburg Formation near the Yakima River in Yakima County, Washington. Seven genera of fishes in four families were collected by Kevin Meeks and James E. Martin, mostly from interbedded clay and tephra in a green claystone near the old clay pit workings. Catfish (Ictaluridae, Ameiurus new species) and sunfish (Centrarchidae, Archoplites) are the most common species; minnows (Cyprinidae) are the most diverse family. The Ellensburg cyprinid assemblage includes a new species of Mylocheilus, rare Ptychocheilus and Klamathella(?), and early Rhinichthys, as well as a plagopterin spine dace, otherwise known from the Lower Colorado drainage. The sucker, Pantosteus (Catostomidae), is known earlier in the Drewsey-Juntura Basin and has a subsequent history in Columbia-Snake River, Colorado River, and Great Basin drainages. Each faunal element is unique in its timing and direction of relationships, suggesting assembly of the fauna during a long prior history in the basin of the Columbia Plateau Province.