"This is an ongoing issue for us.
"We want to make sure we can preserve the values of these incredible places."
She said DoC was always working to strike the balance between the number of people using the parks, with preserving the integrity of the environment.
Allan said DoC was in discussions with iwi about a possible trial to cap numbers entering Tongariro National Park.
She said she was confident the country's national parks were being looked after and maintained in an exceptional way by Te Papa Atawhai, DoC in conjunction with its various partners where that is appropriate.
"We are pretty confident there is sufficient resourcing there to do a good job."