Why not? Because P12N-Mountain is carrying the Sacramento State-at-Colorado game on Saturday afternoon.
Remember, the Pac-12 Networks are designed to cater to Pac-12 fans. This is certainly annoying to you SUU fans, but you're not really part of this equation.
The Thunderbirds-Bears matchup will be seen on the regional networks in Arizona, Northern California and Southern California. Which doesn't do anybody in Utah any good.
SUU-Cal will also be seen on national P12N feed, which is the only way you can see it if you live in Utah. And if your cable system carries the national feed.
Locally, Comcast carries the P12N national feed on Channel 410 as part of its Sports Entertainment Tier of programming.
And Channel 410 is not in high def. So it will be a bit blurry for SUU fans who can see it.
Could be worse. If you're a Sacramento State fan, you'd have to drive to Utah or Colorado to see your game on TV at all.