You could spend forever exploring Behind The Rocks, but it also makes a great overnight bikepacking trip. Side roads go on forever and there is always Pritchett canyon and a return via Spanish valley, or loop out to the canyon rim and explore old mining roads. A popular route is Kane Creek to Behind the Rocks. But I wanted to stay out of the creeks of Kane Creek. This area is full of adventure. It is covered in the NatGeo maps and the Latitude40 maps. The 24 hour race loop is good, but also head out towards Kane Creek Canyon Rim and check out that view.
An easy to follow loop is to follow the BTR Safari Route, visit Tuk arch and head back towards Pritchet Arch. Really so much area to adventure. Just pack a ton of water and go. There is 0 water out here, and in the summer it a blast furnace of heat. Keeping that in mind, have at it!