The Chieftains fell into an early 21-0 hole en route to a non-league loss on the road.
River quarterback Mason Priddy threw two touchdown passes — the first a 33-yarder to Keith Blau followed by a 29-yarder to Atticus Kurtz.
Isaac Bibb-O’Neill also scored for the Chieftains on a 6-yard run.
Columbia River (3-6) is into the postseason for the ninth straight year, this time as the No. 4 seed from the 2A Greater St. Helens League. The Chieftains will travel to face top-ranked Tumwater (9-0) in the state preliminary round.
CLARKSTON 35, COLUMBIA RIVER 20
Col.River 0 7 7 6–20
Clarkston 21 7 0 7–35
First quarter
C — Tru Allen 29 pass from Kaiden Frazier (Steve Baiye kick).
C — Nathaniel Hoffman 37 pass from Frazier (Baiye kick).
C — Eddie Berglund 23 run (Baiye kick)
Second quarter
C — Berglund 37 run (Baiye kick)
CR — Keith Blau 33 pass from Mason Priddy (Roman Castro kick)
Third quarter
CR — Isaac Bibb-O’Neill 6 run (Castro kick).
Fourth quarter
C — Will Sliger 5 run (Baiye kick)
CR — Atticus Kurtz 29 pass from Priddy (kick failed)
Individual statistics
Not available.