Vanishing Treasures Program


Tusayan Pueblo, granaries tucked into small cliff recesses, the ruins of mining camps in obscure side canyons, and the remains of Havasupai wikiups on the South Rim, are all vital links to Grand Canyon’s long and diverse human history. However, these and other cultural sites containing architectural remains, such as stone walls or wooden fences, in Grand Canyon National Park face threats from erosion, burrowing rodents, vandalism, and increased visitation. Years of insufficient funding for preservation of architectural sites further threatened prehistoric and historic ruins at Grand Canyon and in other park service areas throughout the arid West.

Black and white historic photo of a worker wearing coveralls placing a large block of stone onto the wall of a prehistoric structure.
Worker resetting masonry, Tusayan Pueblo (1930s) NPS Photo

The prehistoric and historic architectural remains in our western national parks and public lands were literally vanishing. The Vanishing Treasures Program was established in 1998 by Congress to meet critical preservation needs for architectural resources, or ruins, in national park areas. Vanishing Treasures provides funding for and implementation of ruins preservation activities.

Grand Canyon National Park is one of 45 National Park Service areas that participate in the Vanishing Treasures Program. The goal of the Vanishing Treasures program is the conservation of architectural remains through research, documentation, and preservation treatment.

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Today, our Vanishing Treasures Preservation Crew is working at Tusayan Pueblo. This pueblo was occupied by the ancestors of modern-day Pueblo people around 1200 A.D. They built the pueblo using local materials, such as Kaibab Limestone rocks and mud mortar. This necessitates frequent repairs in order to keep the site in good condition and safe for visitation.

Archaeologists mapping a structure. NPS/Ellen Brennan

Architectural Research

Grand Canyon National Park contains incredibly diverse architectural remains from the past. Centuries old, prehistoric Native American architectural sites include pueblos, cliff dwellings, granaries, agricultural and water control features, and ancient trail systems.

More recent Native American architectural sites in the park include wikiups, hogans, and sweat lodges. Historic mine buildings, fences, and cabins are evidence of early Euro American use of the Grand Canyon area.

Although some of these structures show the effects of deterioration, many contain remnants of original walls, mortars, plasters, and other features.


Like other types of artifacts, architectural remains provide tangible links to rich cultural histories from the past. Architectural studies teach us about human adaptations to the challenging Grand Canyon environment. They inform us about how Grand Canyon inhabitants might have shared building technologies among themselves and with people in surrounding areas. These studies help us appreciate the cultural traditions reflected in the structures people built and inhabited and how those traditions may be passed between generations.

Unlike artifacts that can be stored in museum facilities and protected, most architecture remains exposed to the elements. Architecture may be impacted by water erosion, animal burrowing, and the effects of gravity. Buildings may be subjected to inadvertent damage caused by visitation or may be damaged or destroyed by vandalism. Vanishing Treasures Program ruins preservation activities conserve architectural remains through condition assessments, documentation, and preservation maintenance (stabilization treatments).

two archaeologists reviewing paperwork, are sitting in front of a stone granary with a door. They are wearing helmets and are roped into the cliff face.
Archeologists conducting architectural condition assessment. NPS/Michael Quinn

Preservation Projects

Archeologists conduct three types of Vanishing Treasures projects: architectural condition assessments, architectural documentation, and preservation maintenance (stabilization treatments).

Architectural condition assessment involves careful inspection of architectural remains to identify the causes of structural deterioration and to determine the extent of damage to architectural elements. Deterioration is commonly caused by water erosion, other natural forces like gravity, and visitation.

Condition assessments help archeologists determine what maintenance activities are necessary to conserve architectural remains and to establish priorities for preservation maintenance activities.


Architectural documentation includes the collection of detailed information about site layout, structural form and outline, building materials, and construction techniques. These elements inform archeologists about the styles of architecture used within a given site and help archeologists understand the building traditions and styles of past cultures. Archeologists use scaled drawings, photographs, measurements of architectural elements, 3D laser data capture and imaging, historic documents, and other data to document architectural remains. This information establishes a baseline from which preservation maintenance can proceed and helps ensure that preservation activities are compatible with the original methods and materials used in site construction.

Preservation maintenance (stabilization treatments) projects aim to slow deterioration of architectural features like masonry walls and wooden beams. At Grand Canyon, these projects are most commonly completed on previously stabilized and interpreted sites like Tusayan Pueblo and Walhalla Glades Pueblo. When working on architectural sites, Vanishing Treasures specialists select mortars, stone, and other materials that are compatible with the original architectural elements. Stabilization materials must provide enough strength and durability to slow additional structural damage without harming original architecture elements. Archeologists test materials to examine their suitability for preservation treatments before using them on an archaeological site.


Preservation Methods

In the past, archeologists and maintenance workers sometimes reconstructed historic or prehistoric archeological sites, such as pueblos, in order to help the visiting public understand life during the past.

Although these reconstructions were well intentioned, they were undertaken without careful documentation or analysis of original architectural elements, and sometimes resulted in the loss of original fabrics and features. These losses sometimes caused archeologists to make inaccurate interpretations of the rebuilt structures and their original functions or uses.

In addition, reconstructions proved costly and difficult to maintain. These experiences prompted a professional movement away from reconstructing ruins to preserving them in their naturally eroded condition.

Mason stabilizing wall in the Bright Angel Pueblo site. NPS/Michael Quinn

Current preservation practices focus on conserving the original architectural elements found at sites. Preservation specialists often first try indirect treatments, such as drainage control or redirecting visitor access by re-routing trails, to reduce impacts on architectural remains.

When indirect treatments are not effective in slowing structural deterioration, direct methods of preservation, such as resetting wall stones and bracing collapsing walls, may be necessary.

Today, archeologists select materials, like local soil for mortar and stones for wall masonry that are similar in appearance to original building materials.

Archeologists also may use modern additives, like synthetic polymers, to add strength to mortars. Such materials are less damaging to masonry and more visually compatible than cements used during early park service stabilization efforts.


Preservation Technology

Advanced digital and computer technologies are now commonly employed by Vanishing Treasures archeologists. Archeologists use digital photography, global positioning systems (GPS), three-dimensional laser scanning and modeling, and computer-aided drafting programs (CAD), to collect, store, and analyze architectural data. Preservation specialists use these techniques to produce digital models and scaled drawings of architectural remains that can be referenced to geographic information systems (GIS).
Stacked tree branches forming a triangular shaped sweat lodge, with an open side (left). A black and white 3D digital image of the same structure (right) was created by laser scanning.
Historic sweat lodge (left) with its 3D digital image (right) created by laser scanning.

(Left) NPS Photo (right) 3D model by Western Mapping Company, Tucson, Arizona


These innovative technologies give preservation specialists powerful tools to create high resolution imagery and to capture architectural information in greater detail. These progressive methods help archeologists better understand the architectural remains found within Grand Canyon National Park and to interpret the human stories that led to their construction and use.


Related Information

Grand Canyon National Park Archaeological Resources

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Canyon Sketches Vol 03 - May 2008
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Canyon Sketches Vol 09 - March 2009
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The Vanishing Treasures Program
Grand Canyon National Park is one of 45 National Park Service areas that participate in the Vanishing Treasures Program. The goal of the Vanishing Treasures program is the conservation of architectural remains through research, documentation, and preservation treatment.

Canyon Sketches Vol 04 – June 2008
Vanishing Treasures Archaeologists Stabilize Transept Pueblo (North Rim)
In late June 2008, archaeologists from Grand Canyon National Park’s Division of Science and Resource Management cleaned and stabilized Transept Pueblo, a two-room ancestral Puebloan structure on the North Rim.


Last updated: July 30, 2020

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