Bonsoir à tous!
Pour Mesa Verde NP, il y a une alerte sur le site officiel du parc concernant Spruce Tree House

Je surveillerai le site car j'irai en juillet mais ça semble râpé.
Spruce Tree House Cliff Dwelling Will Remain Closed
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Date: February 24, 2016
Contact: Cristy Brown, 970-529-4608
In August 2015, a rock fall at Spruce Tree House cliff dwelling prompted park officials to close the site for visitor safety until an analysis and hazard assessment could be conducted. After that initial evaluation was completed in September 2015, it was decided that the entire site should be closed to the public in October 2015.
In November 2015, a select climbing team comprised of National Park Service employees from Chiricahua National Monument, Rocky Mountain National Park and Arches/Canyonlands National Parks completed a technical scaling project at Spruce Tree House. At this time, the arch crack system above Spruce Tree House was inspected and any loose material was removed. However, other rock fall concerns were identified during this process, and
Mesa Verde has determined to keep Spruce Tree House closed for the foreseeable future until a full geotechnical assessment can be performed.
Spruce Tree House may be seen from an overlook near the Chapin Mesa Museum. Rangers will provide guided talks through March 5, 2016. After that date, rangers will be available at the overlook to answer questions. The Petroglyph and Spruce Canyon hiking trails will be accessible by the traditional vantage point, south of Spruce Tree House.
Additional Information
A natural sandstone arch is present in the Spruce Tree House alcove, just above the cliff dwelling. Early stabilization work was performed in the 1940's with additional stabilization work completed in the 1960's. Natural erosion processes, including the settling of the arch, have been affected by the early stabilization work, so modern engineering techniques may be necessary to ensure continued stability of the arch.
Spruce Tree House is the third largest cliff dwelling in the park. As one of the best preserved ancestral Puebloan sites in the Southwest, there are many examples of original architecture including intact roofs, floors, and original plaster designs in the dwelling. Due to the accessibility of the site and its self-guided access, it is the most visited cliff dwelling in the park.
Due to the complexity of the project and the significance of Spruce Tree House cliff dwelling, there is a four-phase sequential approach planned. The first phase is to use Light Detection and Ranging (LiDAR), a remote sensing method employing a laser to obtain a complete structure profile. Also, geotechnical information will be collected to be integrated in the numeric modeling and analysis. Phase Two will consist of geotechnical engineers conducting detailed three-dimensional computer-based analyses of the original condition, 1960's stabilization and probably 2016 stabilization, using information from Phase One as a chronological modeling sequence. Phase Three will include developing plans, specifications, and gathering necessary information to complete stabilization work. Phase Four will be the performance of the work.
-NPS-