This fall, they will be separated by 45 minutes. This spring, possibly by only a dozen or so draft picks. Among their peers in the histories of their respective schools, by thousands of yards.

They are the quarterbacks Marcus Mariota of Oregon and Sean Mannion of Oregon State. The former is a junior from Hawaii with 5-to-1 odds to win the Heisman Trophy. The latter is a senior from northern California who could set the Pac-12's career record for passing yardage by October.

These are heady times indeed to be watching college football in the Willamette Valley, which raises the question: Is this the best combination of quarterbacks to ever play at Oregon's rival universities at the same time?

To reach that lofty title, they must still separate themselves.

In a recent survey of former Oregon and Oregon State coaches and quarterbacks, Mannion and Mariota join other combinations such as OSU's Jonathan Smith and UO's Joey Harrington, who each were fixtures from 1999-2001. There was the combination of native Oregonians Kellen Clemens (a Burns-raised Duck) and Derek Anderson (first of Scappoose, then of Reser Stadium) from 2003-04. Farther back, Heisman winner Terry Baker of OSU faced Bob Berry, who led Oregon to three straight winning seasons for the first time in 25 years.

Other combinations exist, too, of course. But it would be hard to find another duo who could end their careers at such lofty heights as Mannion and Mariota.

Mannion's numbers — specifically his 10,436 career passing yards — are staggering. He enters his senior season already holding 11 school records and 31 career starts, battling through injury and a quarterback derby with Cody Vaz throughout his career before emerging as the cemented starter.

But is there a difference between most prolific passer in school history and best quarterback in school history?

Beavers fans fondly remember Smith for helping direct the best season in school history in 2000, one that included an 11-1 record, a Pac-10 co-championship and a 41-9 whipping of Notre Dame in the Fiesta Bowl. Anderson and Matt Moore are still in the NFL after successful careers in Corvallis. And, of course, Baker dominated in a different era of quarterbacking.

What OSU coach Mike Riley sees missing from Mannion's career is a marquee bowl win.

"That would probably be the icing on the cake," Riley said.

South of Corvallis is Marcus Mariota, the junior Oregon quarterback and Heisman Trophy candidate who's been discussed as a potential No. 1 NFL pick next spring. Saturday evening's season opener against South Dakota is only Mariota's 27th career game, yet he could break Oregon career records for total offense and passing touchdowns against the Coyotes. By season's end, his name could be atop the record book in completions, passing yards and yards per attempt, alongside the records he already holds for passing efficiency and completion percentage.

The Ducks' tradition of quarterbacks is long and storied and includes everyone from Norm Van Brocklin to Dan Fouts and Joey Harrington. Yet the debate about where Mariota fits in that line is already over, according to former UO quarterbacks and coaches.

"He's the best ever," former coach Mike Bellotti said. "I think it's already the time to say he's the best because of his winning percentage, accuracy and ability to break the big play."

Everything is big with Mannion and Mariota, except for their egos. Both are described as selfless decision-makers whose biggest fault on the field is their reticence to lead by voice. They are also united in their biggest challenge entering 2014: a lack of proven receivers for both the Beavers and Ducks.

"This year will show a lot about the two because in the absence of those big producers outside in Brandin Cooks and Josh Huff, these guys will really have to produce," former Oregon quarterback Mike Jorgensen (1981-84) said. "If they can stay at that level like always, there's no question these guys are the best ever at their schools."

Riley, who offers plenty of perspective on the history of quarterbacks in the Northwest, also recently pondered the magic question. He said one would be hard-pressed to find two college quarterbacks in one state — except for perhaps the giants like Texas and California — boasting more talent and accomplishments entering 2014.

But do Mariota and Mannion make up the best duo to ever quarterback the Civil War rivals at the same time?

"I don't want to rank them," Riley said. "... all those old guys might get mad at me if I said this was the best. These guys are really good. They're really, really good.

"It's gonna be fun to have two guys play like this through the year, and then we'll see them both go on and play for a long time (in the NFL)."

-- Andrew Greif and Gina Mizell