I think you underestimate Southron ambitions. Also, if the CSA won the war with the aid of the British and French, expect US/Canadian border issue to much much more violent than in our history.
The “Deseret” area southern border would be the Colorado river. Sorry, but the Grand Canyon is simply too great a barrier. Don’t let the nice straight lines between Arizona and Utah fool ya, two adversarial entities would settle on the natural barrier. Likewise for Missouri and Kansas, that which is north of the Missouri river would almost certainly flip to “Union” control, south to CSA control.
West of the Mississippi River, most of the state borders (many of which weren’t set until 10-50 years AFTER the American Civil War) are Lat/Long based, rather than being based on geographic features. I would venture that particular paradigm would not hold along the border areas.
Postmortem Studios 
I think you underestimate Southron ambitions. Also, if the CSA won the war with the aid of the British and French, expect US/Canadian border issue to much much more violent than in our history.
The “Deseret” area southern border would be the Colorado river. Sorry, but the Grand Canyon is simply too great a barrier. Don’t let the nice straight lines between Arizona and Utah fool ya, two adversarial entities would settle on the natural barrier. Likewise for Missouri and Kansas, that which is north of the Missouri river would almost certainly flip to “Union” control, south to CSA control.
West of the Mississippi River, most of the state borders (many of which weren’t set until 10-50 years AFTER the American Civil War) are Lat/Long based, rather than being based on geographic features. I would venture that particular paradigm would not hold along the border areas.