NCAA Football: Arizona at California
USATSI

The rest of the "Four Corners" schools are heading to the Big 12. Arizona, Arizona State and Utah will all join Colorado in the Big 12 starting ahead of the 2024-25 athletic season, the conference announced Friday night. In adding three more Pac-12 teams, the Big 12 in 2024 will swell to 16 programs, the largest membership in league history.

Colorado was the first to jettison the Pac-12 for the Big 12 last week ahead of the Pac-12 finally unveiling a proposed media rights deal that was not received positively. Big 12 presidents unanimously voted to welcome Arizona into the league Thursday and did the same in a Friday meeting for Arizona State and Utah, sources told CBS Sports' Dennis Dodd. The schools' respective Boards of Regents formalized their transitions into the Big 12 on Friday night.

The Wildcats and Sun Devils have called the Pac-12 home since 1978 when they left the WAC, expanding the league from eight to 10 members. The Utes joined in 2011 out of the Mountain West.

"We are thrilled to welcome Arizona, Arizona State and Utah to the Big 12," said commissioner Brett Yormark in a statement. "The Conference is gaining three premier institutions both academically and athletically, and the entire Big 12 looks forward to working alongside their presidents, athletic directors, student-athletes and administrators."

The Pac-12 held a Friday call as a last-ditch effort to keep the league together but ultimately failed in achieving its goal.

Despite Arizona linking with the Big 12 before Arizona State, there was substantial sentiment within both athletic departments that a conference sever was both undesired and unlikely, sources told CBS Sports' Matt Norlander on Thursday. The Wildcats leaving the Sun Devils behind in the Pac-12 would have been "extremely surprising," one high-ranking source said.

Yormark previously stated that the Big 12 only hoped to expand back to 14 members following the departures of Texas and Oklahoma to the SEC. Instead, it becomes the third conference with 16 or more members starting in 2024, joining the Big Ten (18), which added Oregon and Washington from the Pac-12 on Friday, and SEC (16). The Big 12 entered deep discussions about adding all four programs as long as 13 months ago after USC and UCLA left the Pac-12 for the Big Ten.

Where does the Pac-12 go from here?

The already murky future of the Pac-12 now hangs in the balance. Pac-12 commissioner George Kliavkoff delivered an underwhelming media rights presentation to university administrators from the league earlier this week. Those centered around a streaming contract with Apple that would have reportedly paid members around $20 million annually. The Apple-focused media rights package included tiers of incentivization with a significant upside for teams if certain subscription numbers were met, sources told Dodd. 

The Big 12, which has long been focused on expanding with at least two -- if not all four -- of Arizona, Arizona State, Colorado and Utah, is paying its members nearly $32 million annually through its new media rights agreement with ESPN and Fox.

Annual payouts in the Big Ten are even more lucrative at $60 million per school annually through an agreement with CBS, Fox and NBC. However, Oregon and Washington will only receive 50% of the annual share ($30 million with yearly $1 million escalators) after changing conferences, according to multiple reports.

The Pac-12 is now down to just four members: California, Stanford, Oregon State and Washington State. The Mountain West and AAC will both likely be interested in discussing membership with those programs, and independents remains an option for Stanford,a private institution that boasts arguably the nation's strongest athletic department.