Cape Kiwanda sinkholes now a tourist attraction

A second sinkhole, discovered in early May, is about 10 inches away from the first, and measures about 10 feet across and about 30 feet deep. That sinkhole developed within the safety fence of the first sinkhole in the northwest corner of the lower dune.

Cape Kiwanda is a sandstone outcropping, which is naturally much weaker and prone to sudden changes compared with hardier rock, like basalt. While any natural area carries risk, enjoying Cape Kiwanda safely requires visitors to pay special attention, according to the OPRD.

The Lincoln County Leader has reached out to OPRD’s representative Stefanie Knowlton for insight about the sinkholes and the future of the park area at Pacific City.

Lincoln County Leader: At this point, have any other sinkholes occurred and have the original holes gotten larger?

Knowlton: As far as we know, no other sinkholes have formed anywhere at Cape Kiwanda. The two original sinkholes continue to change, however. Over the summer, the sinkholes seemingly filled in with sand moved by the wind. This fall and winter, the sinkholes have continued to grow wider and deeper.

Lincoln County Leader: We understand a report was developed following the discovery of the sinkholes. What has the OPRD learned about the cause of the holes?

Knowlton: From the report, we learned the sinkholes were likely formed by runoff water pooling and eroding the rock underneath the sand and creating a void, according to the Oregon Department of Geology and Mineral Industries report from October 2023. There is also a large cave system under that part of the cape that will eventually fail due to water erosion.

Lincoln County Leader: What has been done and is currently being done to protect the public who would like to visit the area?

Knowlton: OPRD is taking the following safety measures:

• Moved the fence line more than 50 feet south of the sinkholes, which exceeds the DOGAMI recommendation.

• Installed signs warning visitors to stay back.

• Increased monitoring of the area.

• Talking to visitors about safety and respecting the fence boundaries.

Lincoln County Leader: Is the risk of more sinkage enough so that the dunes area would have to be closed to the public?

Knowlton: The hazard near the sinkholes is isolated to this specific location. However, conditions could change as the entire cape is a dynamic environment. We will continue to monitor the changing landscape closely in consultation with DOGAMI and adjust safety precautions as necessary.

Lincoln County Leader: Because of this incident, is the OPRD examining other areas of the Oregon coast as a safety and preventative measure?

Knowlton: OPRD is not specifically examining other park areas for this unique hazard, but as an agency we continually monitor, evaluate and respond to safety concerns at all of our properties based on their unique characteristics.

Cape Kiwanda is a rarity on the Oregon coast because it’s a sandstone outcropping. Sandstone is naturally much weaker and prone to sudden changes compared with hardier rock like basalt. While any natural area carries risk, enjoying Cape Kiwanda safely requires visitors to pay special attention.

We encourage all visitors to be aware of their surroundings and the potential hazards that naturally exist when enjoying some of Oregon’s landscapes. If you have any concerns for your safety at a park, please find a safe location and report your concern to the park office.

Lincoln County Leader: What has been the cost of the Cape Kiwanda State Natural Area sinkholes (monitoring, repairs, fencing, assembling reports)?

Knowlton: It cost roughly $2,000 to move the permanent fence line (we were able to repurpose portions of the old fence), a few hundred dollars to make and post safety signs and ongoing costs for additional monitoring by park staff.

We understand that visitors are naturally curious and may want to see the sinkholes for themselves, but we ask that they respect the barriers in place and observe from a safe distance behind the new fence line.