Flowing southeast on the north side of Oregon Route 22 in Yamhill County, the river receives Pierce Creek and Ead Creek from the , and Cedar Creek from the before flowing under the highway at about RM 57 (RK 92). Continuing parallel to the highway, which lies to its left, the river receives Crooked Creek from the left and Elmer Creek from the right before passing Midway and entering Polk County at about RM 55 (RK 89). Just beyond the county border, Agency Creek enters from the left. About later, the river receives the Rogue River from the left, reaches Grand Ronde, and passes under Grand Ronde Road and Oregon Route 18, a highway connecting the Portland metropolitan area to the Oregon Coast. Shortly thereafter, Rock Creek enters from the right.