A phased program to develop coordinated methods for the survey, analysis, stabilization, and interpretation of the masonry and architectural surface finishes in the cliff dwellings of Mesa Verde National Park, Colorado, has been developed by the Architectural Conservation Laboratory at the University of Pennsylvania with funding from The Getty Grant Program, National Park Service, Colorado Historical Society, The Samuel H. Kress Foundation, and the Ballantine Family Fund. The program is based on a fourfold approach including:

During Phase 1, documentary research on Mesa Verde's architecture, masonry construction and extant surface finishes was undertaken to establish the extent and previous condition of the ruins from the time of excavation to the present. During Phase 2, a detailed conditions survey of the masonry and finishes at Mug House was made by developing and applying standardized nomenclature and objective recording techniques developed by the University of Pennsylvania in 1994. Those areas determined to require immediate emergency stabilization were treated using temporary measures. This methodology was developed during Phase 1 (Summer 1994).

 

During Phase 2, work focused on the characterization of the finishes and mortars, including layer structure, execution techniques, composition and overall physico-chemical properties, and surface decoration. This was examined in conjunction with the finishes typology considered in relation to existing information on the broader cultural implication of the architectural use, technology and meaning. Deterioration mechanisms were also studied and an environmental monitoring program was designed and installed by English Heritage researchers John Fidler and Barry Knight for assessment of site conditions.

Stabilization techniques were tested in the laboratory on actual samples and facsimiles as well as on site in order to evaluate the most appropriate treatment options. A conservation treatment program was designed, tested, and applied over several years during Phases 3 & 4 at Mug House as a model program for the later stabilization of the surviving prehistoric plasters at the park (Phases 5-7).

Mug House was selected as the model site at Mesa Verde for several reasons. First, the site was carefully excavated (1959-61) and well-documented (Rohn 1971). It is an excellent representative example of an intact, medium-size Mesa Verdean cliff dwelling. Secondly, although the masonry at Mug House has already been stabilized, the surface finishes were in very poor condition and required detailed conditions documentation, assessment, and treatment immediately before any further deterioration and loss occurred. Thirdly, Mug House contains some of the most significant and intact remains of prehistoric wall and floor plasters at Mesa Verde. This includes both plain and painted earthen plasters and, in particular, a plastered and symbolically painted kiva (Kiva C) of exceptional quality. As many as 9 layers of plaster and painted designs have been identified in Kiva C, allowing the possibility of developing and illustrating a chronological sequence of architectural surface finishes through non-destructive technical examination and analysis.

Eighty years of documentation of the architectural fabric of the cliff dwellings in Mesa Verde NP have made it clear that the extensive and unique plasters and painted finishes covering the interiors and exteriors of the structures are deteriorating at an alarming rate.

At some sites, such as Kiva C, Mug House, up to 25% of this fragile fabric has been lost since excavation in 1960. A general inventory of the location and condition of all plasters in 18 cliff dwellings was undertaken in 1985 and 1987, verifying and documenting the severity of the problems. From 1994-1996, a model conservation program was initiated by the University of Pennsylvania to document, characterize, and monitor the plasters and painted finishes in preparation for pilot treatments (Phases 1-3). On the basis of this research, implementation of a stabilization and conservation program is now underway.

Phase 4, accomplished in 1997, concluded the fieldwork by completing the model conservation treatments required for the stabilization and protection of the surface finishes at Kivas C, E, and F, Room 28 at Mug House, and Kiva E at Long House. Phase 5 was conducted during the summer of 1998 and included a full range of projects:

 

Phase 6, conducted during 1999, was designated a study season in preparation for a publication and exhibition on the past and present conservation of the site. However, limited work continued at Cliff Palace focusing on the emergency treatment of the mural paintings in Room 121 in Square Tower at Cliff Palace under Frank G. Matero and Jeanne Marie Teutonico (Getty Conservation Institute). Work also continued on the front-country park-wide survey of finish conditions (Rivera and Oliver). The environmental monitoring team (John Fidler and Barry Knight, English Heritage) also returned to assess their data at Mug House and remove the monitoring apparatus and temporary pilot shelters.

The Year 2000 allowed the implementation of the above model program through unprecedented funding from a 1.5 million dollar matching grant from Save America's Treasures. A two-year project was designed to complete the finishes conditions survey and assessment of the 18 front-country alcove sites and complete the stabilization and conservation of Cliff Palace, the park's largest and most visited cliff site. An international and multi-disciplinary team of conservation experts including Jeanne Marie Teutonico of the Getty Conservation Institute together with graduate students undertook conservation work at Cliff Palace that included conditions survey, materials analysis, treatment, and environmental monitoring. In addition, a prototype for a kiva protection shelter was constructed and installed based on the previous research.

The Mesa Verde project allowed participants the opportunity to address first-hand

through field experience the theoretical and technical issues surrounding the stabilization and interpretation of archaeological and ruin sites. The ultimate objectives of the program are to record, stabilize, and interpret this fragile architectural fabric for scholars and the public alike and to integrate simple preventive conservation practices into park maintenance so that further loss and damage can be prevented and future major remedial intervention avoided.