Next friday we're going to be in Debeque around 11:00 (flexible) to explore the Little Book Cliffs Wild Horse Area. It's about a 40-50 mile loop of easy dirt roads through some beautiful desert where the wild horses live. Any 4x4 should be fine, it's more about where you are then what you are doing.
This is a gravel bike course through the main loop of the area. They kicked off this race just before the pandemic so it never really got traction, but I'd expect to hear more about it in the coming years. It shows the roads in the area, easy and well maintained. There are a couple of spurs that look good too.
The North Soda Spur