Casa Grande Ruins
Administrative History
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The protection and preservation of a precious and valuable resource was utmost in the mind of Sylvester Baxter when he sought to convince influential Bostonians to lend their support to have the Casa Grande ruins preserved for the future. It was through the efforts of these people that the first preservation and protection measures were taken in 1891. This early stabilization work, combined with future endeavors, has attempted to stop natural deterioration and repair damage. Although it has frequently proved to be a maze of dead ends, the preservation objective has remained a vital part of the monument management. The construction of shelter roofs over the Great House, combined with major stabilization efforts in 1906-08, 1924-28, 1955-56, and 1967, has slowed natural deterioration. Besides these endeavors, experimentation with chemical preservatives occurred in the 1930s, 1940s, 1970s, and 1980s in an attempt to harden the earthen remains against erosion. The ultimate, but not final, solution in this ongoing effort for stabilization has been the use of a commercial cement binder product called Daraweld-C to produce "Amended Mud" which is coated on the remains by using whisk brooms.

Because it was the most visible and spectacular part of the prehistoric remains, the first preservation efforts focused on the Great House. In 1891 a $2,000 appropriation was used to underpin the walls with brick as well as fill the largest, lower wall holes. The surface of the brick in these holes was set back one inch from the face of the walls to allow the brick to be covered with a concrete plaster. Some lintels over doors and windows were replaced and the cavities above them were filled with brick. Three internal braces were used to support the south wall. In October 1902, S. J. Holsinger did not approve of the use of brick or concrete on the ruins. He felt that restoration work should be done with original material. If an ambitious program had been developed at that time to periodically repair the ruins with caliche, the walls probably would not have suffered as much. Even if such a plan had been developed, the frequent lack of preservation funds would have prevented its implementation. Holsinger's major accomplishment, however, was not the development of a policy to use natural material for repairs, but the design of a corrugated iron roof supported on redwood posts which was built over the Great House in 1903. [1]

In the period 1906-08 J. Walter Fewkes spent two winter seasons at Casa Grande. Part of his work involved exposing more than half of the room walls and the entire enclosure walls in Compounds A and B. This effort amounted to uncovering some 100 rooms. Fewkes did not replace the earth over the walls. The intent, in keeping the walls exposed, was to provide an additional attraction for visitors. Occasionally, decisions regarding interpretation made preservation more difficult. Fewkes recognized that the uncovered walls would be subject to deterioration, but, he thought, the greatest threat to the walls would come from moisture undercutting or sapping them. In Compound A, his solution to keep water away from the base of the walls was to grade the surface and dig a series of drainage ditches to conduct water to the northeast corner of the compound. From that location the water was diverted to a depression 200 feet northeast of the compound. In addition Fewkes placed a layer of concrete along the base of the Compound A walls to prevent undermining. In Compound B, Fewkes dug a drainage ditch around the outside of the compound wall. [2]

Left uncovered, the compound and room walls soon began to erode from the action of rain and wind. Beginning with his annual report for fiscal year 1910, Pinkley noted the erosion, but he concluded that there was no practical way to protect the walls. Consequently, the walls were left to the effects of nature for the rest of Pinkley's first custodianship and that of James Bates, Pinkley's successor. Although he was unsuccessful, Bates did advocate putting a concrete cap on the exposed walls to keep them from crumbling. [3]

When Frank Pinkley returned as custodian in 1918, he began to give some thought to a means by which the exposed walls could be protected. He wrote to National Park Service Director Stephen Mather that he had considered spraying the walls with silicate of soda, but he did not do so. Instead, Pinkley asked Fewkes to send him suggestions for wall protection. Fewkes replied in May 1918, but that letter does not exist. One can only guess that he had not changed his views in the time since he had excavated the walls. When Pinkley sent Mather his idea of the causes of wall destruction in July 1918, he repeated Fewkes' earlier conclusion that water rising by capillary action caused sapping or erosion at the base of the wall. [4]

Despite his concerns, Pinkley received no preservation money until the 1925 fiscal year which began July 1, 1924. Preservation work continued until February 1928 with the initial goal to stop wall sapping. Following that work, a concrete cap was placed on the walls as a means to prevent crumbling of the soil. In the first two years, repair work concentrated on Compound A. George Boundey, who became Pinkley's full time assistant on July 1, 1924, was placed in charge of the work. With two Pima men to aid him, Boundey ran a trench along the inside and outside of the walls for some two feet below the floor line. Then the wall surface was covered with concrete for about two feet above and below the floor level. By the end of April 1925 the base of Compound A walls had been covered in that manner. Soon thereafter and continuing into 1926 the walls were given a concrete cap. Some of the exposed walls were given a concrete coating. Daring the winter of 1927-28, Martin L. Jackson, the Montezuma Castle custodian, supervised the stabilization work. More exposed walls in Compound A were given a concrete coating. Stucco was placed on the concrete coating that Mindeleff had used to cover the great house brickwork in 1891. Concrete plaster was used on two groups of rooms to the east of the Great House and on the multi-story remains to the southwest of that structure. Areas where the concrete wall cap had cracked or broken off were patched. [5]

When Thomas Vint visited Casa Grande toward the end of 1930, he and Pinkley discussed ruin preservation techniques. Pinkley decided that he did not like coating walls with concrete. He found it objectionable because it hid the walls. Consequently, Pinkley and Vint talked about the possibility of using some transparent waterproofing chemical to coat and harden the ruin walls. Toward the end of January 1931, Vint wrote to Pinkley to tell him that he had obtained a gallon of a product called Dehydratine which was manufactured by the A. C. Horn Company. Vint's action evidently caused Pinkley to decide that it was time to more actively seek a chemical preservative. Pinkley replied that he would test the product on the ruins. At the same time, Pinkley sought more information on the subject of waterproofing materials. He wrote to the Bureau of Standards in Washington, D.C. to request a copy of "A Preliminary Report of Exposure Tests on Colorless Waterproofing Materials" published in 1921. Pinkley evidently took one further step to obtain chemical preservatives. In early February 1931, a National Park Service article titled "Solution to Preserve old Masonry is sought" appeared in newspapers almost nationwide. This appeal brought letters from companies in such states as New York, Michigan, Ohio, California, and Arizona with offers to send test samples. [6]

The newspaper article resulted in a flood of chemical preservatives being sent to the monument. When tested on small wall areas, none gave satisfactory results. The Horn Company product Dehydratine #2 turned dark. A liquid "Ankerite", received from the Lucille Chemical Company of Glendale, California, was not quite colorless and it gave the test area a glossy appearance. After four months, it cracked. Product samples continued to arrive at Casa Grande from 1931 into 1934. This parade of products carried such names as Amoglaze, Inwood, Stucco Waterproofing Compound, Oronite Waterproofing, Hornstone Crystals, Forex, Unicrete, Permo #4, and PeneTex. Some companies sent representatives with samples to apply on test areas. In November 1932 an agent of the Air-Spray Company of Washington, D.C. applied two test applications of his material on eighteen small wall areas. By January 1933 the product had cracked and in March of that year it began to peel from the wall. [7]

L. E. Peterson of the Truscon Laboratories in California came on April 20, 1933, to apply his company's product "PeneTex." Since rain had made the walls wet, he had to delay his experiment. Consequently, he talked Custodian Hilding Palmer into letting him remove a small section of the concrete plaster so he could apply the chemical to a dry area beneath the concrete. To their surprise, the wall section under the concrete plaster had decomposed for varying depths. A wall segment that had never been plastered was in better shape than the concrete-covered walls. Peterson and Palmer decided to remove several more sections of wall plaster. They found that the caliche in these areas had also become a powdered mass which fell out when the concrete was removed. In addition these exposed sections contained much greater moisture, even to a considerable depth, than walls which had no concrete covering. The walls had absorbed ground moisture which was prevented from escaping by the concrete plaster. So, they concluded that no wall treatment would be successful until the absorption of ground moisture could be stopped. Peterson suggested that concrete mixed with Truscon Waterproofing Paste should be used as curtain walls to a depth of two to three feet below ground to stop the flow of a major portion of ground water. Once built it needed to be coated with PeneTex. Peterson also advocated that drain tile covered with gravel be placed below the curtain walls. [8]

Hopeful that curtain walls were the answer to ruins preservation, Custodian Palmer requested that a Park Service engineer read Peterson's report. Assistant Engineer J. B. Hamilton came to the monument and examined the ruins. He consented to a curtain wall, but he cautioned that the trench for such a wall should not be dug straight down. To do so could cause the ruin wall to become unstable. Hamilton also warned that the concrete in a curtain wall needed reinforcement and expansion joints. As a result, Palmer decided to discontinue the experiment of spraying the walls with waterproofing material until curtain walls could be built. He, no doubt, expected to wait for some time to install curtain walls because he had no money. [9]

Fortunately for Palmer, the federal depression era work programs came to his aid. The brief Civil Works Administration program gave Palmer his opportunity to have curtain walls built. On November 21, 1933, he applied to have CWA monies used at Casa Grande for ruins preservation. Between December 1933 and February 1934 CWA workmen laid 600 feet of curtain wall along the south and west walls of Compound A. In addition, by grading the inside of the compound, the northeast water drainage, as established by Fewkes in 1907, was changed to the northwest corner. [10]

At the same time as the Casa Grande curtain wall work, the Engineering Section of the National Park Service field office in San Francisco obtained some CWA money to use for experiments with caliche and adobe preservatives. That office made an arrangement with Stanford University for laboratory space in which to conduct the work. F. A. Kittredge contacted Southwestern Monuments Superintendent Pinkley and asked that he send 100 adobe brick made from Casa Grande soil so that the waterproofing experiments could begin. He proposed to first perform a physical and chemical analysis of the adobe soil so that a determination could be made if a potential preservative would cause a chemical reaction with the soil. Kittredge hoped to find a colorless waterproofing fluid that would not peel or crack. In addition he sought to design a concrete cap which would keep wall tops dry. [11]

Pinkley had Casa Grande Custodian Palmer send ninety-seven adobe brick to Kittredge. Palmer evidently had no objection to turning over the preservative testing to the San Francisco field office. At the same time, however, he wanted to make sure that the new Park Service laboratory received a sample of his favorite waterproofing chemical. Within days of sending the adobe to Kittredge, Palmer wrote to M. J. Cavalier of the Truscon Steel Company in Phoenix and asked that he send a sample of PeneTex to be tested. [12]

In addition to Palmer's help, Kittredge asked companies that produced chemical preservatives to send samples of their products to the engineering laboratory. By March 28, 1934, fifty-two different preservatives had been received. Of that number, forty-three had been tested by August 18, 1934. Kittredge felt that only one of the forty-three chemicals had proved worthwhile. That solution, named Por-Lox, came from the Truscon Laboratories. His assessment, however, proved premature. By early March 1935 Por-Lox failed an ultra-violet test. [13]

When all the commercial preservatives failed to pass National Park Service tests, the field office engineering staff set out to develop its own product. Frederick Martius began with celluloid solutions, but any mixture over one percent proved glossy, and glossy material would not penetrate. Soon, however, Martius produced a colorless chemical that did not gloss but penetrated and was not affected by ultra-violet rays. He called this vinyl resin in acetone and toluene solution NPSX. On March 20, 1935, field work began at Casa Grande with that chemical. He covered several test areas in the southwest corner of Compound A with two coats of two, three, three and one-half, and five percent NPSX solutions. NPSX worked for two years, but when it was examined in 1938, in the third year, it failed to repel water. In fact the NPSX-treated areas absorbed as much moisture as the untreated walls. These results were very disappointing because NPSX cost too much to apply every two years. Consequently, it was back to the 1931 starting point to find a means to preserve the ruin walls. [14]

In mid-1939, frustrated with watching the old cement plaster scale off the rapidly deteriorating ruin walls, the Casa Grande Custodian A. T. Bicknell decided to experiment with "bitudobe." At the time, the Civilian Conservation Corps work force used this product to cover the exterior of the adobe buildings being constructed at Casa Grande. On June 27 Bicknell had two small wall sections of the Clan House coated with bitudobe. After a month it seemed to be effective. As a result, the custodian sought official approval to put bitudobe on all standing ruin walls. The value of bitudobe was never determined, however, because no funds were available to purchase it. At that point Bicknell settled for stabilizing ruin floors by using a caliche base with a top dressing of bitumuls oil. The CCC workers employed on that project had all the floors covered by September. [15]

Although the 1930s tests failed, Casa Grande and Southwestern Monuments personnel could not give up on chemical preservatives. Charlie Steen seemed determined to find some liquid that would work. In the spring of 1940, he removed the concrete cap from the east half of the Clan House. Then he dug trenches beside and under those walls in which he placed a six-inch curtain of caliche waterproofed with emulsified asphalt. As the final step he sprayed the wall area with two coats of "Themec" which was an emulsified cement paint. In a month the Themec turned lavender and in a year it had cracked and peeled. [16]

Monitoring equipment was installed for the first time in the Great House during the summer of 1940. Brass rods were placed across the corners of the building in such a way as to show wall movement. Monel metal rivets were imbedded in the top of the center walls of this structure to measure wind erosion. [17]

In 1941 heavy rains damaged the ruins. Because no satisfactory stabilization method had been found, the damage was accepted as an act of nature and no action was taken to repair the walls. Charlie Steen, however, undertook to backfill Compound F as a means of saving the remaining walls from further erosion. That compound had been excavated in 1930 and left exposed. Steen then applied for soil and moisture conservation work funds to backfill Compound E. The concrete cap at this site had failed and allowed serious wind and water erosion. He completed that job by March 1942. This compound was covered to a level of six inches above the walls by using the old excavated soil. Following the Compound E work, Steen backfilled the excavated area of Compound D. This site had been partly uncovered by Fewkes in the 1907-08 era. [18]

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Last Updated: 22-Jan-2002