I camped on BLM land just outside the park near the Hop Valley trailhead just off the Kolob Terrace Road. Kolob Terrace Road goes in and out of the park. There is a rough road going west just before you re-enter the park. We were in a passenger car and we not able to get very far off the paved road but we were just looking for a place to sleep as we had a permit starting the next day.
We checked out this area and I wasn't a fan to camp there. Instead We camped in Rockville on BLM Smithsonian. They do allow fire as long as you are 3.9 miles away from Rockville city boundaries.