Rivalry games on tap as Pac-12 football season nears end

Two down, four to go.

Stanford and USC have secured victories in rivalry games this season, but there are four left in the Pac-12 with both berths in the league championship game still on the line.

Colorado controls its own destiny when it hosts Utah on Saturday. With a win, the Buffaloes claim the Pac-12 South Division outright. If Colorado loses, it drops into a tie in the standings with USC, and the Trojans, who have finished conference play, will win the South because they beat the Buffaloes.

The showdown between Washington and Washington in the Apple Cup on Friday night will decide the Pac-12 North.

The league title game is set for Dec. 2, at Levi's Stadium in Santa Clara.

A look at the conference rivalry games this weekend in the Pac-12:

WASHINGTON vs. WASHINGTON STATE

Series began: 1900.

Series record: Washington leads 70-32-6.

Trophy: Apple Cup.

Why it's a big deal: The game is for the Pac-12 North title, which has gone to either Sanford or Oregon since the league expanded in 2011.

This year: The game is crucial to the Huskies (10-1 overall) to preserve a shot at the College Football Playoff. Washington is currently No. 6 in both the CFP rankings and the Top 25.

OREGON vs. OREGON STATE

Series began: 1894.

Series record: Oregon leads 63-46-10.

Trophy: Called the Civil War, the game's unofficial prize is the Platypus Trophy, awarded each year to the alumni association of the winning team. Lore has it that the platypus was chosen because it has a duck bill and a beaver tail, so it represents the mascots of both schools.

Why it's a big deal: The winner will avoid finishing in the Pac-12 North basement. Three teams - Oregon, Oregon State and Cal - are currently 2-6 with one game to go.

ARIZONA STATE vs. ARIZONA

Series began: 1899.

Series record: Arizona leads 48-40-1.

Trophy: Territorial Cup, which is recognized by the NCAA as the oldest rivalry trophy.

This year: At 5-6 overall, Arizona State needs one more win to become bowl eligible. The Sun Devils have made the postseason for the past five years. Arizona hasn't gone winless in conference play since 1957.

UTAH vs. COLORADO

Series began: 1903.

Series record: Colorado leads 31-28-3.

Trophy: It's been called the Rumble in the Rockies, but there's no official trophy. The rivalry was dormant for several decades before it was revived when both teams joined the Pac-12 in 2011.

This year: The No. 21 Utes fell out of the running for the Pac-12 South title with a loss to Oregon last weekend. The No. 9 Buffaloesmust win outright to claim the Pac-12 South and secure a spot in the league championship game. Should Colorado win the title game, it goes to the Rose Bowl for the first time ever.