Recent history in the rivalry game that dates to 1894 will be this year on the side of the No. 3 Ducks (10-1, 7-1 Pac 12), who have won six straight in the series against their neighbors to the north.
But the Beavers (5-6, 2-6) have a history of pulling off big upsets at home, including a 35-27 victory over then-No. 7 Arizona State at Reser Stadium earlier this season.
Helfrich grew up on the Southern Oregon Coast in Coos Bay. While both of his parents and his brother went to Oregon, Helfrich himself went to Southern Oregon University where he was starting quarterback from 1992-95.
He remembers going to then-Parker Stadium in Corvallis as a teenage and getting ''just drenched in one of those low scoring games there.''
''As we sit today, I was always on the correct side of the rivalry,'' he joked.
Riley has been tied to Oregon State and Corvallis since his father Bud Riley was an assistant for legendary Beavers' coach Dee Andros, also known as the Great Pumpkin for his girth and penchant for wearing orange windbreakers.
Riley attended his first Civil War as a seventh grader.
''I remember Thurman Bell, who's still coaching here at Roseburg, making a great play to win the game,'' said Riley. ''My dad was coaching the DBs. It was really fun to be a part of, and I feel thankful to this day to get involved in the game.''
The Civil War is tied for the fifth most-contested rivalry in football, and it's the oldest west of the Rocky Mountains. Here are a few other things to note about the annual game.
EARLY DAYS: Oregon State - then Oregon Agricultural College - won the first one 16-0. In 1916, Oregon defeated OAC 27-0, giving the Ducks a 6-0-1 regular-season record and their first-ever appearance in the Rose Bowl, where they defeated Penn 14-0.
PYRAMID PLAY: The 1933 game was notable because Oregon's extra-point attempt was blocked by Clyde Devine, who was lifted in the air by his teammates. The Ducks nonetheless defeated Oregon State 13-3, and the so-called Pyramid Play was later banned by the NCAA.
TERRY BAKER: In 1962, the Beavers and Heisman Trophy-winning quarterback Terry Baker trailed 17-6 at halftime but dominated the second half. Baker's 13-yard touchdown pass to Danny Espalin in the fourth quarter sealed a 20-17 victory. Baker remains the only Heisman Trophy winner from an Oregon school, although that may change this year with Marcus Mariota.
TOILET BOWL: A futile 0-0 tie on a blustery and wet day in November 1983, featured 11 fumbles, five interceptions and four missed field goals. It would go down as the last scoreless Division I college football game.
ROSE BOWL BOUND: The Ducks entered the 1994 Civil War tied with USC for the Pac-10 championship and needed a win to clinch their first Rose Bowl berth since 1957. Trailing 13-10, Danny O'Neill drove the team 70 yards, hitting Dino Philyaw for a 19-yard touchdown with 3:47 to play, giving Oregon a 17-13 victory.
HARRINGTON TEARS: In 2000, the No. 8 Beavers denied the fifth-ranked Ducks a trip to Pasadena with a 23-13 victory. Afterward, quarterback Joey Harrington wept in the arms of his father, John, who played the same position for the Ducks in the late 1960s and never beat Oregon State in three tries.
BEAVERS DENIED: In 2008 the Beavers were looking toward their first Rose Bowl in 44 years with a victory in the final game when the Ducks romped to a 65-38 win in Corvallis. The next year the game was dubbed the ''War of the Roses'' because the winner was guaranteed a Rose Bowl berth. Oregon won 37-33.
LAST YEAR: The Beavers nearly pulled off an upset at Autzen Stadium. Oregon State took the lead on Victor Bolden's 25-yard run with 1:39 left. But Mariota orchestrated a drive that was capped with a 12-yard touchdown pass to John Huff with 29 seconds to go for a 36-35 Oregon victory.