The thesis is a treatment evaluation for the Sacristy Window micritic limestone at Mission San José y San Miguel de Aguayo in San Antonio, Texas. To complete a comprehensive treatment analysis it was necessary to use past research conducted seven years prior and to further analyze the stone before conducting laboratory experiments. The goal of the treatment testing program is to be site-specific to address the problems of the Sacristy Window limestone. To accurately characterize the stone it was necessary to conduct a re-survey of relevant conditions and document the construction of the site. In addition, small samples were taken from flaking areas for laboratory analysis. Results were analyzed to identify deterioration mechanisms. This step ensured that the treatment evaluation addressed pertinent causes of deterioration at the site. The testing program was organized in three phases. The first two were addressed in this thesis and the third is included in the recommendations. Phase I research included the analysis of Sacristy Window limestone samples and similar quarried Cordova Cream limestone intended for the testing program. Phase II tests first included salt-contaminated and control stones separated into six treatment groups (G through L). This treatment program was designed for use with a Hydroxilated Conversion Treatment (HCT) as a preconsolidant. Treatments included salt-impregnation with calcium sulfate dehydrate and sodium nitrate into quarried Cordova Cream limestone, desalination, salt-immobilization and preconsolidation. All treatment groups were analyzed with Scanning Electron Microscopy (SEM) to determine efficacy of the preconsolidation treatments.