Vernacular Architecture: Towards a Sustainable Future, 2014


Restoration Informed by Archaeology of a Mexican-American Adobe Ranch Hous


Ione R. Stiegler, FAIA, Stephen Van Wormer, Susan Walter


Taylor & Francis Group, 2015

Restoration Informed by Archaeology of a Mexican-American Adobe Ranch House (pgs 679-684)


Using the interdisciplinary approach, of Architectural adobe knowledge with the trained eye of an Archaeologist, the studies purpose was to determine if there was any association or identification of the building as the Trading Post of Jonathan T. Warner and his family from 1849 to 1851, and its subsequent destruction by fire. To support the conclusions the archaeological study acquired data about the structural evolution of the building, focusing specifically on foundation construction and the presence of packed earthen surfaces or floors. The long history of the Ranch House evolution was apparent in several features encountered during excavation, documenting a building that expanded over a period of time and informing the restoration design. The restoration of the Ranch House applied the rigorous Secretary of the Interior’s Standards for Restoration with the State of California’s Historic building code and Americans with Disabilities Act (ADA) requirements.

The Ranch House at Warner’s Ranch is a landmark in the history of the American West. The location is associated with Mexican exploration, the frontier period in U.S. American westward migration, the California Gold Rush, the first transcontinental overland mail lines, and pioneer cattle ranching. The Ranch House is located in the broad, relatively flat San José Valley (Valle de San José), which is situated in the mountains in the northeastern portion of San Diego County, California. Since the late 1840s the area has been commonly known as Warner’s Ranch after Jonathan Trumbull Warner, who lived in the valley during the 1840s and early 1850s when it was an important camping stop on the Gila Overland Trail to California. Warner operated a store and trading post at a fork in this trial from 1849 to 1851. In 1857 the current ranch house was constructed by the Carrillo family. By the late 20th century the ranch house still stood, but the location of Warner’s store and trading post had been forgotten.1


How can the memory of a building be lost so easily? How can the precise location of a building, that had been used by thousands of immigrants and had constant habitation on the site, be lost? How could this have happened in so short a time span, less than 70 years? These were the final questions the researches were left with after the conclusion of both the restoration and archaeological test excavation of the historic resource. The research team consisting of archaeologists, historic preservation architects, cultural landscape specialists and historians had been working at the site in three distinct episodes since 1997. The initial research, 1997-98, was a Historic American Building Survey (HABS). In 2003-2004 the work effort included the writing of a Historic Structure Report (HSR), and initial archaeological test excavations. The last effort, in 2010-2011, included the complete restoration of the adobe house to a house museum, the support facilities for the use and archaeological test excavations. In 1997, the origins of the extant Ranch House were in dispute, as local lore and the majority of historians held that the current house was rebuilt upon the ruins of the original store and trading post built by J.T. Warner. A small minority of historians and a single contemporaneous mapping survey offered a different location, nearby but not identical to the current location. It was within the frame work of this ongoing disagreement that the initial research commenced.

2     History of development of the site

On January 24, 1848, nine days before the Treaty of Guadalupe Hidalgo ceded the present southwestern United States and ended the Mexican War, gold was discovered at Sutter’s Mill in northern California, launching the California Gold Rush. Within a year, 80,000 people had traveled to California from around the world (Greeley 1987:14). Thousands of gold rush emigrants from the U.S. and Mexico used the Gila River overland trail. San José Valley, by this time more commonly known as “Warner’s” or “Warner’s Ranch,” was the first well watered camping spot that the emigrants reached after weeks of crossing cactus and creosote covered desert sands.  Both livestock and travelers needed rest and refurbishment, many camped in the valley to let their livestock graze and regain strength while they attempted to restock badly depleted supplies.

Overland journals indicate Warner built the trading post sometime between September and November of 1849. (Chamberlain 1849). By November 28, 1849, however, he had completed the building and was open for business (Aldrich 1851). Cornelius C. Cox who recorded on December 28, 1849:  “Arrived at Warner’s Ranch and finding good grass, lay by one day. The road here forks, one leading to San Diego, the other to Los Angeles. Warner has established a grocery and butchery for the accommodation of the emigrants – and this being the first place at which supplies can be obtained, the emigrant has been subjected to the severest extortion . . . ” (quoted in Wright 1961:22, ft 1).

Located on the east side of the knoll overlooking Buena Vista Valley (Reynolds 1870), the house and store consisted of a rectangular adobe building with a thatched roof divided into two rooms. A thatched ramada (described as a shed by Benjamin Hayes in 1850) on the front covered an exterior patio and work area. When Benjamin Hayes visited the building in December 1850 he saw several partially cured hides pinned down in front of the patio.  Freshly butchered beef hung on a pole in the shade under the ramada near the building’s front door (Hayes 1850). Additional outbuildings were located around the structure (Sackett 1856). A blacksmith shop was located on the west side of the compound (Reynolds 1870).

Warner’s prosperous trading post would come to a sudden and abrupt end.  Beginning in November 1851 Antonio Gara, chief of the village at Agua Caliente Hot Springs, organized local tribes in an unsuccessful revolt to oust American settlers from the land. On the night of November 21 Gara’s followers murdered four Americans. Early the next morning they attacked Warner’s trading post (Bibb 1976). The Indians “rifled” the house of everything it contained (San Diego Herald 11-27-1851). They then set it on fire. Warner lost everything in the house and store (valued at almost $60,000) and an estimated 400 cattle (District Court, Case 56, Statement of Case; Sackett 1856; Warner 1886:45-46). In February 1852 Russell Sackett passed through Warner’s Ranch and saw the former trading post and store “destroyed and in ruins, and not occupied” (Sackett 1856). The following year other visitors noted the abandoned ruins of Warner’s former store. But soon thereafter the knowledge of the original location of the trading post was lost and local lore evolved misplacing the extant adobe ranch house as having been built upon the exact foundations of the destroyed trading post built by Warner.

The property was then deeded in 1858 to Vicenta Sepulveda de Carrillo.A year prior to their receiving title, the Carrillos had built the original portion of the current Ranch House at Warner’s Ranch (Warner-Carrillo Ranch House) on the south side of Buena Vista creek. From 1857 to 1861 the Gila trail was used by the overland mail service. The overland mail was first carried by the San Antonio and San Diego Mail Line from July 1857 through August 1858, and then the Overland Mail Company from September 1858 through June 1861. Establishment of the overland mail constituted the first communications and transportation link across the continental United States, and the ranch house served as an important stage stop. The ranch passed through several owners and was used to raise horses, sheep or cattle. The land continues today as a cattle ranch. (Fig. 1).

3     Description of the Built Resource

The Ranch House is an almost square adobe building consisting of a central one and a half story wing with a tapanco style attic, and shed roofed wings added to the north and south sides. Overall, the building measures 41 feet 9 inches by 46 feet. (Fig. 2). The roof was originally covered with wooden shingles and later with corrugated sheet metal.  A 6 foot wide veranda (covered porch) attached to the north side

was temporarily removed in 2004 as part of stabilization work on the building.

The original Central Wing is a two room adobe building measuring 18 feet 7 inches by 41 feet 9 inches. The North Wing and South Wing additions are also 41 feet 9 inches in length. The South Wing is 14 feet wide, and the width of the North Wing is 13 feet 7 inches. Each has three rooms. All the rooms had wooden floors in various states of disrepair. In order to accommodate the northerly descending slope the floor of the northern wing is approximately 22 inches lower than that of the Central Wing.

All walls were made of adobe block with stone foundations. However, several features in the building give testimony to a long, multi-phased, and complicated structural evolution. On the east end of the building the walls of the Southern and Northern Wings were pulling away from the Central Wing, indicating that the center two-room section was built first and the north and south portions were added to it as separate construction episodes. In the east wall of the North Wing, at least 5 different building episodes could be documented in the various layers of adobe block (Fig. 3). Along the south and west sides of the South Wing, the original adobe walls were either removed or badly eroded during the late 19th or early 20th centuries and replaced with a crude wooden frame covered with board and batten siding. During the late 19th century, two wood framed room additions were built onto the west side of the Ranch House. These had been removed by the late 20th century.

During the mid-20th century the building was used as a ranch bunk house. It was abandoned in the

1960s and fell into a state of general disrepair. By 2004 the adobe house was in a very deteriorated condition and in danger of collapse. Walls on the north and east sides as well as the northern porch had fallen. Exposed portions of the remaining adobe walls were eroding. Repairs with incompatible materials had accelerated rising damp and had caused further erosion of the adobe walls. (Fig. 4)

4     The Findings and Questions of the Studies

4.1     1997-1998 HABS Study

With the known historical background and the local lore that the resource had been built upon the exact foundations of the destroyed trading post built by J.T. Warner, the research team began their analysis of the resource. All members of the team were curious to see the evidence of the 1851 fire. To the team’s surprise and bewilderment, no evidence of either a substantial fire or of sequential building on the ruins of prior walls could be found. Observable construction history of the building showed that the ranch house started as a two-room structure which matched the descriptions of the trading post; adding support to the contention that the current ranch house was the former two room trading post. Regrettably, at this time the budget had not allocated for archaeological testing. So while the building was thoroughly documented, the origin of the building was still indeterminable.

4.2     The 2003-2004 HSR, Stabilization and Archaeological Study

Having left the site in 1998 with both unanswered questions and a seriously deteriorating structure highly susceptible to seismic damage, the team was eager to help the owners find grants to finance further work on the resource. The funds were identified and the work effort was budgeted to include the temporary and permanent seismic stabilization of the adobe ranch house, the preservation of the associated wooden and adobe barn and initial archaeological test excavations.

4.3     The 2010-2011 Restoration/Archaeological Study

The hope of the team was that, with judicious placement of test pits (units) alongside the original two-room structure’s foundations, an ash layer would be found and confirm the origin of the building as that of the trading post that had burned.  Test pit after test pit was dug, revealing many interesting aspects of the building, but finding no evidence of ash from the 1851 fire. The mystery of the origin of the ranch house continued.

The team and the owner acquired a third round of funds for the final step of the restoration. Included in the funding was archaeological testing at both the current resource, the ranch house and at a nearby site thought by some to be the Jonathan T. Warner Trading Post and Store Site. (Fig. 5). Complete details were described in an unpublished two volume report entitled, Two Forks In The Road: Test Excavations Of The Ranch House At Warner’s Ranch (Warner – Carrillo Ranch House) and Site of Jonathan T. Warner’s House and Store by Stephen R. Van Wormer and Susan D. Walter of Walter Enterprises in July 2011

4.3.1     Ranch House Research Design and Results

The archaeological research program had two distinct areas of focus. One was the examination of the Warner’s Ranch House. The other was directed at characterizing the remains at the potential Jonathan T. Warner Trading Post and Store Site.  Specifically, the excavation and analysis program focused on two research issues for the ranch house.

  1. To determine if any association or identification of the building as the Trading Post of Jonathan T. Warner and his family from 1849 to 1851, and its destruction by fire could be established.
  2. To acquire data about the structural evolution of the building, focusing specifically on foundation construction and the presence of packed earthen surfaces or floors on the inside of the building under the present wooden floors.

Foundations and Findings

The long history of the Ranch House evolution is apparent in several features encountered during excavation. The foundations document a building that expanded over a period of time.  Although all are cobble or field stone footings typically used for supporting adobe block walls, each is different. On the south wall, smaller water worn cobbles make up the bottom course of stones with larger water worn granite cobbles on top. On the center wing in the Entry Room, a single course of irregular shaped granitic field stones was used. On the north wall the bottom course of the foundation is made up of large granite field stones that show little wear from water, with smaller water worn cobbles in the top course. The three distinct ways in which these foundations were assembled strongly suggest that they were not built by the same individuals, and certainly not at the same time.

In addition to wall foundations, interior excavations revealed remains of early floors and surfaces. In the Entry Room (101), two earthen floors and a wooden floor constructed with square nails give testimony to the extended use of the Central Wing. A lower packed earthen floor was the original floor in this room. It was later replaced with a second upper packed earthen floor. Finally, the current wooden floor was put in. The fact that it is constructed entirely with square cut nails strongly suggests that it was built before the early 1890s and certainly dates it before 1910.

Excavation in the interior of the south wing uncovered a cobblestone and mud mortar grouted floor in Room 103. In Rooms 102 and 103, compact surfaces were found below a layer of loose sandy soil unlike the packed earthen floors in Room 101, these layers consisted of the packed light brown-tan sandy loam soil found throughout the site. Excavations inside the North Wing uncovered the remains of a packed earthen floor in Room 107.

Finally, it should be noted that such improvements as wooden floors, stone facings on the base of the east and west wall, and board and batten siding along the south and west sides of the south wing appear to be part of a general rehabilitation of the building that can be documented by its appearance in photographs taken during the 1890s and first decade of the 20th century. It would appear that during the Vail ranch period beginning in 1888, the building was rebuilt as a family home for the company’s foremen and achieved its current configuration and appearance.

Artifact activity profiles for the South and Central Wings were dominated by munitions, household, and garment items. Conditions of the soil layers where the artifacts occurred preclude a definite direct association between the material and the activities that occurred in these rooms. In the North Wing artifact activity profiles were dominated by hardware, personal, garment and consumer items.

The most significant artifact concentration found on the exterior of the building was in Unit 04-8. Artifacts included consumer, kitchen, garment and household items as well as building materials. In addition, various pieces of Native American pottery were found as well as a stone mano, and a stone metate fragment. This assemblage was dominated by kitchen items, followed by household items, lithics and hardware. The deposit appears to be a kitchen and household refuse pit dating from the 1860s when the Carrillo family occupied the Ranch House. It contained the same types of materials and similar activity profiles as refuse deposits from the same period encountered at the J.T. Warner Trading Post and Store Site.

Finally, no evidence for the occupation of this site or the building by the Jonathan T. Warner family from 1849 to 1851 was encountered. There were no substantial artifact deposits dating from this time period and no evidence of a significant fire that could be attributed to the Indian attack and destruction of Warner’s house and store in 1851.

4.3.2     Jonathan T. Warner Trading Post and Store Site Research Design and Findings

At the Jonathan T. Warner Trading Post and Store Site the excavation and analysis program focused on the following research issues:

  1. If any association or identification of the Ranch House building and site as the residence of Jonathan T. Warner and his family from 1849 to 1851, and its subsequent destruction by fire could be established?
  2. What archaeological features remain?
  3. If a features period of construction and use could be identified?
  4. What artifact deposits remained?
  5. If the artifacts period of deposition/use could be identified?
  6. What the resources can tell us about domestic lifestyles, economic and social activities?
  7. What comparative relationships between other archaeological collections in Southern California can be demonstrated for the middle of the 19th century?

The data recovered as a result of the above research goals was combined with the archival research data to identify and describe 1) site function and evolution, 2) architectural methods and traditions, and 3) ethnic, social, and economic influences at both sites.

In 2004, a survey was made of the knoll directly north of the Ranch House at Warner’s Ranch on the north side of Buena Vista Creek, where Deputy Surveyor William Reynolds recorded ruins in 1870 identifying them as the location of Jonathan T. Warner’s Trading Post and Store Site. A number of features were visible at the time; A series of mounds and depressions, small former reservoir, a rectangular cobble foundation that measures approximately 15 by 20 feet and was open on the south end, potentially the former blacksmith shop. Two 3 by 3 foot test units were excavated in the area between the reservoir and the cobble foundation where gophers had brought artifacts to the surface in order to obtain a sample that might provide some possible dates for the site’s occupation and give some insight into the activities that occurred there. The units were excavated in 6-inch levels and terminated at 12 inches below the surface on a naturally occurring layer of dense cobbles. A sheet deposit of kitchen refuse was identified but results were inconclusive concerning the dates of deposition (Van Wormer and Walter 2004, 2008).

In 2010 the site was again surveyed and a map prepared. The site covers the flat knoll top, covering an area approximately 190 feet east-west by 172 feet north-south. Nine features were ultimately identified through survey and excavation.  (Fig. 6).

To summarize results of archaeological investigations at the Jonathan T. Warner’s House and Store Site, the remains represent a large complex of buildings. Due to the limited amount of testing that occurred at all of the features except F, findings are tentative and somewhat ambiguous. Originally built and occupied by J.T. Warner and his family, the site appears to have been reoccupied after Warner abandoned it following its destruction by the Indians in 1851. This conclusion is based on the discovery of two packed earthen floors in southwest portion of Feature B, and the deposition of artifacts manufactured after 1851 in Feature F. As a result of this reoccupation, more work is necessary before it can be determined what parts of the complex originated with Warner and what are the results of later rebuilding.

5     Summary

The restoration of the Ranch House thoughtfully reconciled the rigorous Secretary of the Interior’s Standards for Restoration with the State of California’s Historic Building Code and Americans with Disabilities Act (ADA) requirements. After decades of neglect, the effort required rebuilding missing adobe and wood framed walls, as well as roof features. This was all accomplished while saving as much original material as possible, such as the wooden ceiling beams, original interior paint surfaces, doors and walls; retaining historic fabric being a crucial element to a restoration of a national landmark. While long lost features were re-exposed, such as the original cobble stone floor paving, new features such as a fire suppression system and seismic stabilization were intricately laced into the resource. (Fig. 7).

For many decades it was believed that J.T. Warner had built the original portion of the Ranch House at Warner’s Ranch. This was based on the fact that the Ranch House was precisely at the fork in the road to San Diego on what was then recognized as the Overland Trail. It therefore was a perfect match for the descriptions of Warner’s trading post (Wright 1961). However, it can now be conclusively proven through interdisciplinary architectural documentary and archaeological evidence that the Carrillos built the original portions of the current Ranch House at Warner’s Ranch (Warner-Carrillo Ranch House) in 1857. It was built on the south side of Buena Vista creek directly opposite the site of J.T. Warner’s burned out trading post and store on the north side of the canyon (Flanigan 1996; Reynolds 1870).

The interdisciplinary approach of architecture and archaeology used in this study is easily reproducible with other earthen architecture projects. The archaeologists trained eye in reading the nuances of shifts in a soil’s layering is paramount for projects of this type.


Aldrich, Lorenzo D. 1851. A Journal of the Overland Route to California and the Gold Mines.  Alexr. Kirkpatrick, Lansinburgh New York.  Reprinted 1966 by Readx Microprint Corporation.


Bibb, Leland E. 1976. William Marshall, “The Wickedest Man in California:” A Reappraisal.  Journal of San Diego History, 22 (1):11-25.

Chamberlin, William H. 1849. Lewisburg to Los Angeles in 1849:  The Diary of William H. Chamberlin. In Gold Rush Desert Trails to San Diego and Los Angeles in 1849, Brand Book Number Nine, edited by George M. Ellis.  San Diego Corral of the Westerners, San Diego. pp. 47-62.

District Court, Case 56. 1856. J. Mora Moss vs. J.J. Warner, October 2, 1856. Records on file San Diego History Center Research Archives.

Greeley, Michael N. 1987. The Early Influence of Mining in Arizona. In History of Mining in Arizona, edited by Michael Canty and Michael N. Greeley. Mining Club of the Southwest Foundation.  Tucson.

Hayes, Benjamin. 1850. Diary entries for January 13 – 17, 1850.  Quoted in The History of Warner’s Ranch and its Environs by Joseph Hill.

Reynolds, William. 1870. Survey of the Valle de San Jose, including Field Notes of Valle de San Jose, August 1870 MS, in Silvestre de la Portilla, Valle de San Jose, California Private Land Claim, Docket 531, MS, in Microfilm Record Group 49, National Archives and Records Center, Perris California.

Sackett, R.1856.Testimony of R. Sackett August 13, 1856.  District Court, San Diego County, Case No. 56,  J. Mora Moss vs. J.J. Warner.  San Diego History Center Research Archives.

San Diego Herald. 1851- . Issues cited in text.  San Diego City Library, Central Branch. 1858

Van Wormer, S.R. & S. D. Walter. unpubl.  Two Forks In The Road: Test Excavations Of The Ranch House At Warner’s Ranch (Warner – Carrillo Ranch House) And Site of Jonathan T. Warner’s House And Store. San Diego. (available on line at

Warner, J.J. 1886. Testimony of J.J. Warner February 15, 1886, Superior Court Case 594, Downey Vs. Pico. Records on file San Diego History Center Research Archives.

Wright, William Lawton. 1961. The Warner Ranch-Butterfield Station Puzzle. Reprinted from The Western Brand Book, Los Angeles Corral, Los Angeles, California.