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Battle Against Mountain Pine Beetles Launched at Mount Rushmore National Memorial

Mountain pine beetles, Kurt Repanshek photo.

Tiny mountain pine beetles -- that black speck near the axe head is one -- are chewing through the forests of Mount Rushmore National Memorial. NPT file photo.

They're inventorying trees at Mount Rushmore National Memorial, with an eye out for trees that are infested with mountain pine beetles.

Those tiny insects can lay waste to lodgepole forests if they gain enough of a foothold by boring into the trees' trunks and killing them. Earlier this year officials at the memorial began working on a plan to combat the beetles, and the first on-the-ground step is inventorying the forests on the grounds to gauge beetle infestations. That work started Friday.

These trees are currently hosting the newest generation of pine beetles and have been killed by the beetles. Pine beetles in green infested trees typically leave the trees in July and August to find new host trees. With the help of South Dakota State University and the South Dakota Cooperative Extension Master Gardeners, Mount Rushmore will be surveying the forest to identify and mark green infested trees. Once these trees have been identified, they will be cut down and dried out to remove and kill the immediate pine beetle population that is in the park. This process will be done every year to identify any new beetle infestations.

The second phase of the plan will begin Tuesday to protect the large-diameter, high-value trees within the visitor areas. High-value trees have been identified as trees larger than 10 inches in diameter and ones that contribute to the forested views of the memorial. If these trees were gone, visitor views of the memorial would look very different. The trees will receive a preventative insecticide spray that will ensure the forested views of the memorial will remain intact.

Mount Rushmore has identified more than 700 trees to be sprayed during the month of June. Carbaryl 4L insecticide spray is the chosen spray for this project. It has proven success in the Black Hills and has also been used in Rocky Mountain National Park to combat the MPB. Trees will be sprayed on their trunks by spray units on the ground. While the spray is being applied to the trees, many visitor areas may be closed to the public.

Actions to ensure the health and safety of park visitors and staff include park closures to keep sprayed areas secure. Areas that have been sprayed will be closed to visitors and staff for approximately 3-5 hours while the carbaryl dries on the trees. Once the spray is dry, the area is safe to re-enter. Signs will be posted near the sprayed areas to identify trees that have been sprayed. Spraying is scheduled to occur in the early morning, with areas closed to the public until noon or 1 pm.

Areas will be sprayed in sections and include trees along the Presidential Trail, around the historic Sculptor’s Studio and along the roadways.

Memorial officials hope that these proactive and preventative measures will protect the park’s forest from the worst damage caused by the current MPB epidemic. The most active area of MPB infestation and highest concentration of tree mortality is in close proximity to the memorial and the oncoming infestation has recently been observed within the park as well.

The current outbreak appears to be larger and more widespread than historically typical. Mount Rushmore’s MPB Assessment and Action Plan was developed to address the current epidemic and identify actions that officials hope will return the forest to a more historic and sustainable condition that can naturally protect itself against future pine beetle infestations.


Pine beetles can only infect trees that are already weakened by other factors, mostly by stress due to drought. A healthy tree will use resin to seal the wound by the beetle and kill it. And the beetles are part of the ecosystem. They are now reaching higher elevations, because really strong winters have become rare, but these infections are natural processes And I really wonder if they should be interrupted in areas that are covered by the Organic Act.

I've often wondered about the MRC. The beetles, while annoying at times, are part of the natural system. Plants need control methods as well. As predators keep herds healthy be eating the weak, so do the beetles keep the forest healthy. Now I'm no expert by any means, but it doesn't make sense to this average person.

A comment about the article and a comment about the comments. First, I think the status of Rushmore as one of the top destinations in the country makes it important to preserve a certain sense of the mystique of the area. It really is an entry point to nature but not necessarily a natural habitat anymore, more like a Disneyland type of area so I think it very important to keep the 700 pines alive both for safety reasons (dead trees fall) and for appearance.

Secondly, as far as comments about the effects on the natural cycle, I'm with you. However, only a tiny, tiny, fraction of the Rushmore forest will be sprayed. Thus the natural process of die-off and regeneration will take place. This is also the strategy at Rocky Mountain National Park in Estes Park, Colorado where only about 5000 acres of more than 270,000 acres are being sprayed.

The Pine Beetle Infestation that we are experiencing is not part of any natural process. It is nature that has gone wild. The human race is to be stewards of the land - we have failed but that does not preclude us from stepping in to help even out what we have messed up. To just let the pine beetle follow some natural course is naive at best. As far as the healthy pines fighting off the infestation - it is well past that stage - the infestation is so severe that they cant. The destruction caused by this infestation is to great. The long term effects of this infestation will be greater. We are wasting natural resources that have been provided to us by nature. As a land owner in the Black Hills and trying to fight this blight - cleaning up my part of the forest and using it wisely - it seems to be a daunting task. Places I have traveled to in Montana, Wyoming and South Dakota have been hit hard and are now scared for many years to come - meaning polluted rivers and streams, increased CO2 into the air, soil erosion, lost income to many -- the list goes on. All of North America has been hit We should all gather together and preserve in saving these resources. The pine beetle must be controlled and not allowed to run a muck. We must also use our resources wisely and not allow them to be wasted.

They are a natural predator for the trees, but in the past were not able to do so much damage because the temperatures in the winter would get cold enough to kill them. There is a very possible link between the pine beetle becoming more rampant and global warming, as warmer winters allow more of the beetles to survive. This is not a natural process or a way to help the forests. Entire forests are getting wiped out, this is unprecedented

Surely an infestation of beetles should be considered a natural phenomenon. Even if it has been agravated by global warming, isn't it still 'natural'? If man is changing the environment, then by all means allow nature to adapt to that change. Isn't that natural? I wish that we and our governments would work harder to stop global warming, but we're just not.

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