The reason behind this particular blanket ban has been attributed to the amount of noise as well as nuisance complaints that were lodged against the use of such drones. Of course, that is the least of the concerns, since park visitors too, worry about the safety of native wildlife.
Jonatan B. Jarvas shared, “We embrace many activities in national parks because they enhance visitor experiences with the iconic natural, historic and cultural landscapes in our care. We have serious concerns about the negative impact that flying unmanned aircraft is having in parks, so we are prohibiting their use until we can determine the most appropriate policy that will protect park resources and provide all visitors with a rich experience.”
Looks like there is no place for drone warning systems at national parks then.