Three options currently are being considered to deal with natural erosion of the arch over Spruce Tree House at Mesa Verde National Park/Rebecca Latson file
How to keep the sandstone arch above Spruce Tree House at Mesa Verde National Park from further collapse is being discussed by the National Park Service, which is reviewing three options, including one to let nature take its course.
The popular attraction, which houses the third-largest cliff dwelling in the park, with 130 rooms and eight kivas, has been closed to the public since October 2015 because of concerns that layers of sandstone could peel away from the arch at any time and fall on bystanders below. Spruce Tree House may be seen, however, from an overlook near the Chapin Mesa Museum.
Back in 2016, the Park Service pointed out that "[E]arly stabilization work was performed (on the arch) in the 1940s, with additional stabilization work completed in the 1960s. Natural erosion processes, including the settling of the arch, have been affected by the early stabilization work, so that modern engineering techniques may be necessary to ensure continued stability of the arch."
Now the Park Service is debating whether to:
- Let natural erosion continue without trying to stabilize the arch and keep the attraction closed to the public
- Stabilize the arch by various methods, possibly including rock bolts; remove loose materials and detached rock slabs; treat existing cracks to prevent the flow of groundwater between the arch and the alcove that houses the cliff dwellings; install concrete supports; and install monitoring equipment to detect movement. Once the stabilization measures are completed, the site would reopen to the public.
- Stabilize the arch as outlined in option two, but keep the site closed to the public.
Public comment is being taken on the options through January 6, 2022. The Park Service says input received during this period "will be used to refine the concepts, identify issues, and ensure that we have the information needed to move forward in the planning process."
A newsletter outlining the project can be found here, and comments can be left there, as well.
Once the options are finalized, the proposal will go through another public review process as outlined by the National Evironmental Policy Act before a final solution is chosen.
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Comments
Closing this to the public should never be an option. Why even bother saving it if it cannot be seen by the public? It is a public treasure as are all National Parks.
I'm pretty sure the ancient ones who built this site would opt to let nature take its course. That's my vote also.
There's been steps taken to protect some natural resources (such as famous trees) but that was more about reducing human effects. Maybe also protecting prominent trees from fire like those at Sequoia NP.
However, the erosion of sandstone is natural and in fact what produced what we see today. There was discussion of protecting Delicate Arch by encasing it in plastic, but in the end that wasn't done. It shouldn't be done as erosion is inevitable.
Others have tried something similar, including at Old Man of the Mountain in New Hampshire. They tried rerouting water flow to reduce erosion, which I suppose is reasonable. But then they used glue, metal reinforcements, cement, etc. to try to delay the inveitable. It still collapsed.