Aren’t tied to the BIG. BYU/Utah and UofA/ASU
The CA, WA, OR schools are all tied to the BIG at least every other year
ESPN could broadcast the BYU game in the afternoon and the ASU/UofA game at night
There are tons of rivalries on the East Coast and MidWest
Utah’s population is small compared to most. Actually outside of CA the population in the West is pretty small