Marysvale Bridge, Spanning Sevier River on Rio Grande Street, Marysvale

Source document Quoted word for word from HAER UTAH,16-MAVA,1-. Not written, edited or summarised by this site.

The Marysvale Bridge is a single span, wood, double intersection Warren pony truss and is one of two known bridges of this type. The bridge was constructed by the Piute County Road Commission under the authority of the State Road Commission.

Source document Quoted word for word from HAER UTAH,16-MAVA,1-. Not written, edited or summarised by this site.

Don Southworth, Office of Public Archaeology, July Marysvale Bridge HAER No. UT-57 (page 2) II. HISTORY A. AGRICULTURE, MINERALS AND THE BRIDGE The town of Marysvale was settled by Mormon pioneers (members of the Church of Jesus Christ of Latter-Day Saints) in These people were looking for good arable land on which they could grow crops and raise livestock but it was the discovery of minerals in the surrounding mountains that contributed most to the town's growth. While the mineral resources dominated the economic scene, it was both mining and agriculture that were ultimately responsible for the need and construction of the Marysvale bridge. Initially, mining in the Marysvale area concentrated on prospecting for gold, silver, lead and copper ore found in the nearby mountains.

The Deer Trail Mine, discovered in contained high grade gold and silver ore. In the expanded Deer Trail Mine was still one of the largest producing and richest mines in the state, fl] Marysvale Bridge HAER No. UT-57 (page 3) Another mineral resource, alunite, was discovered around the Marysvale region in Alunite is a source of potash alum or potassium sulphate. These by- products in turn are used in producing glass, medicines, aluminum salts, refractory bricks, alundum (an abrasive), calcium aluminate (plaster), sulphuric acid and sulphur, fertilizers and explosives. At the time, most potash salts consumed in the United States had been mined in foreign countries. The significance of the Marysvale deposits lay in the size and "remarkable purity" of the veins.

[2] It was thought that though the Marysvale deposit was "not of such magnitude as to afford a source of all the potash salts now consumed in the United States, it may prove to be an important factor in providing an American supply that will perhaps be especially available to local and western markets, particularly in meeting the demand for higher- grade salts." [3 ] With the outbreak of World War I in Europe in the supply of potash from foreign countries was greatly reduced and German imports were completely cut off. Marysvale Bridge HAER No- UT-57 (page 4) Because of this, the Marysvale deposits became even more important to U.S.

chemical industries and farmers as it was "the only alunite, or other ore high enough in alunite to be workable." [4] One of these deposits lay northeast of Marysvale across the Sevier River. Although the Marysvale bridge was constructed prior to the demand for commercial mining of alunite in the vicinity, it became an important access to those resources in the ensuing years. B.

Construction Chronology

The original construction date for the Marysvale Bridge is not known. It appears that the bridge was constructed about the year This is the first year that the newly organized State Road Commission began to take charge of the state road system and reported their progress in the Utah Public Documents, which is a bound report on the various state agencies. The State Road Commission's first report consisted of entries listed by county. The section on Piute County shows a photograph with a caption that reads, "State Highway Bridge Over Sevier River at Marysvale". The Marysvale Bridge HAER No. UT-57 (page 5) photograph is of the bridge with a horse and buggy near the west end of the structure.

This is the first recorded mention of the bridge and it would appear from the photograph that the bridge is fairly new. Thus, the Marysvale Bridge was constructed in or prior. While the bridge remained principally unaltered through the succeeding years, it began to show signs of wear. Shortly after the beginning of World War II, the deposits of alunite in the hills east of the Sevier River became important for the war effort and the bridge became an important access to these deposits. In according to Cloys Seegmiller (personal communication, the Kalunite Co. under the Defense Plant Corporation, opened the White Horse Mine northeast of Marysvale. The alunite was extracted from the earth and carried by truck to the Rock Crusher across the bridge.

The ore was then loaded on to Denver and Rio Grande railroad cars for the trip to Salt Lake City for further processing at Kalunite's mill located at 500 West and South. At the mill the ore was processed into potash and alumina. The potash was used in the manufacturing of ammunition in Marysvale Bridge HAER No. UT-57 {page 6) the state while the alumina was shipped by rail to the northwest for the construction of airplanes. As the White Horse Mine began operation it became clear that the wooden bridge across the Sevier River would never support the vehicles and their loads. Cloys Seegmiller was one of the men employed by the Kalunite Co. and put to work reconstructing the bridge.

Modifications began with the dismantling of the bridge and re-use of the old timbers as a pattern for reconstruction while the metal components remained intact. Later, in the bridge was re-decked with new wood. III. THE BRIDGE A.

Description

The Marysvale Bridge is a single span double intersection Warren pony truss constructed of inch wood timbers. This structure has wood pile piers and concrete abutments. The bridge web consists of two panels of double intersection Warren truss diagonal bracings with inclined endposts. The three vertical Marysvale Bridge HAER No. UT-57 (page 7) support braces are each six feet high and the bridge measures eight feet four inches high from the deck to the top of the upper chord. Total length of the bridge is eighty-six feet with the top chord measuring thirty-one feet ten inches (31 ' 10" ) long. The bridge rests upon stone and concrete abutments at each end and on two concrete piers as well as two timber post piles.

The deck is of four inch thick wood planks that measure twelve inches wide and sixteen feet ten inches long on wood stringers. The structure is held in place with five iron cords that attach to the bottom of each incline post and run the full length of the underneath side of the bridge. The vertical members consist of iron rods bolted to the top and bottom cords while the top and bottom cords consist of inch timbers held together with metal straps six feet (6' ) long, three inches wide and held with six (6) bolts. The bridge railing runs the full length of the structure and is constructed of two-by-fours. Marysvale Bridge HAER No. UT-57 (page 8) B. MODIFICATION The bridge underwent a major modification in when it was re-built at the beginning of WW II .

This modification was needed to strengthen the structure for the increased weight load. This increase in weight came as the vehicular traffic changed from horse and buggy to ore carrying trucks from the White Horse mine. The Kalunite crew given the job of rebuilding the bridge first dismantled the structure and used the timbers as a pattern for the "new" bridge. The metal parts which were intact were re-used in the new bridge. While the bridge was under construction a temporary wood stringer bridge was employed to carry traffic across the river. When the new bridge was erected the timber piles from this stringer were left to support the new bridge structure. The pattern for this new bridge was followed closely and red pine was used as the construction material.

This bridge has remained as is until the present. Marysvale Bridge HAER No. UT-57 {page 9) The only other modification to the bridge occurred in At this time the deck planks were replaced after the old wood deck began to deteriorate. The bridge has under gone minor change as the elements and traffic have effected the structure. The iron rods beneath the bottom cords have become slack and the structure is now dependent upon the wood piles and the concrete piers to support the structure. No other changes are evident. C.

Ownership and Future

The bridge is presently owned by the city of Marysvale and plans have been made for abandonment of the bridge in situ because of its structural decay and unsoundness. A new concrete bridge will be constructed across the Sevier River, northwest of the old bridge. IV. FOOTNOTES 1. Salt Lake Tribune, 7 February p. 2. The Salt Lake Mining Review, 30 January p. 13 3. Ibid., p. 13. 4. Ibid., 15 June p. 19. Marysvale Bridge HAER No. UT-57 (page 10) V. BIBLIOGRAPHY A. BOOKS State of Utah, Index to Public Documents Volume I, First Biennial Report of the State Road Commission, B. PERIODICALS Loughlin, G. F. , "Recent A1unite Developments Near Marysvale and Beaver, Utah," Department of the Interior, United States Geological Survey, Bulletin ).

Higgins, Will C., "The Attractions of Marysvale, Utah," The Salt Lake Mining Review, Vol. 11 No. 8, July 30, The Salt Lake Mining Review, "The Alunite Deposit Near Marysvale," Vol. 13 No. 20, January 30, The Salt Lake Mining Review, "Utah Alunite to be Developed," June 15, Marysvale Bridge HAER No. UT-57 (page 11} The Salt Lake Mining Review, "Potash from Utah Alunite," June 15, C. NEWSPAPERS The Salt Lake Tribune, 7 February Marysvale Bridge HAER No. UT-57 (pa^e 12) o *. -o ac f * S3 ? * 3 ill tr- -3> e ft n il \J h EJ Marysvale Bxidge IIAER No. UT-57 (page 13) # m Z X c * > 30 5o m !li