Cobbled together a highway blog for UT 9 from five trips to Zion National Park over the years. Regarding the 2016 Fall Mountain Trip the day I took UT 9 was a hell of a driving day, I also took all of UT 12 and most of UT 24 to reach Green River (three National Parks in one day to boot). Personally UT 9 is one of my favorites, especially when it can be enjoyed in the off season for Zion National Park:
http://surewhynotnow.blogspot.com/2018/09/2016-fall-mountain-trip-part-11-utah.html