Most NP do not allow OHVs,ATVs,however if you are road legal and have plates,you can ride in Park.Do not have a piped bike and expect not to be stopped!Be cool and all is well.Many of the NPs have BLM land or National Forest next to them,so you camp outside NP and hike in or some have access in and parking for OHVs,just a short walk to shuttle busses,and with an America Beautiful pass ,all is FREE.Utah is extremely TH and OHV friendly,around their parks.Az is also great,just be street leagal and all is well.For just a TV go small inverter,but need more batts no matter what.