Depending on where you are flying out of by SLC, you may or may not care to come down alongside SLC going south to Utah lake, east of Eagle mountain and west of Provo. (SLC controllers were great, and you will talk with several) Work your way west and down by Delta, then south to Cedar City (which makes a midway stop if taking in easy steps), on to Saint George. We flew Tuckup corridor but you could pick any. If tuckup then you could head to area of Clark Memorial KCMR and follow I-40 to Flagstaff.
I also got a recommendation for flying around to east of SLC with I 80/84 and down to Heber City,...and I think west by Orem, just north of Provo
We flew opposite direction this summer. Early morning flight with no problems.
FBO at Flagstaff will tie you down with big ratchet straps. (I don?t think they read the recommended working load for those,... I prefer something with a bit more strength,.... but at least they can get them snug)