Yes, pets are required to have leashes at Hawaii Volcanoes National Park. The park’s pet policy states that all pets must be on a leash no longer than six feet long and under the physical control of their owners at all times while in the park. This includes trails, roads, campgrounds, and other areas within the park boundaries. Pet owners are also responsible for cleaning up after their animals and disposing of pet waste in trash receptacles. Failure to abide by these regulations may result in fines or removal from the park.