The
Grande Ronde Valley is a valley in
Union County in northeastern
Oregon, United States. It is surrounded by the
Blue Mountains, and is drained by the
Grande Ronde River.
La Grande is its largest community. The valley is long, north to south, from Pumpkin Ridge to Pyles Canyon, and wide, east to west, from
Cove to the Grande Ronde River's canyon. Its name, fittingly, means "great circle".