Not sure I follow. You're from Northern Arizona and would like trees for a change of pace? Much of Northern and eastern AZ is heavily forested. Bullhead city is in the desert so I can understand that! Easiest would be to head to Williams on I-40. We love Grand Canyon Railroad RV resort but it doesn't have a lot of trees. Just down the road is Circle Pine which is forested. Williams is a fun route 66 town with lots to do. Grand Canyon is not far, Bearizona animal park, Deer Petting Zoo, lakes and more nearby.
Near Williams is Circle Pine.
Near Alpine is Coronado Trail
Near Flagstaff is Woody Mountain
If you do not need full hookups, many of the forest service campgrounds are heavily wooded such as Rim or Ponderosa.
Eastern AZ has some of the most scenic campgrounds. Big Lake, A1 Lake, Horseshoe and many others.