Utah? I don't have concrete suggestions but check out
The Radavist Rubber Side Up - he's in LA and loves riding in the desert. He's done some cool trips in that area, Owens Valley, Death Valley, the Sierra, and Utah as well - some more MTB than road. Might have route suggestions that capture your interest.
Endless Summer in Owens Valley: A Tale of Three Gargantuan Climbs The Radavist
Cycling Through History in Death Valley National Park The Radavist
A Sunday Spin on Artist Drive in Death Valley National Park The Radavist