Corduroy Creek Bridge, Spanning Corduroy Creek at Highway 60, Show Low

Source document Quoted word for word from HAER ARIZ,9-SHLO.V,2-. Not written, edited or summarised by this site.

Spanning Corduroy Creek on U.S. Highway 60, milepost miles southwest of Show Low; unplatted Township 8 North, Range 21 East; Navajo County, Arizona. UTM: USGS Quadrangle: Long Tom Canyon, Arizona (7^ Minute Series, Date of Construction: Designer: Arizona Highway Department Builder: Pleasant-Hasler Contracting Company, Phoenix AZ Fabricator: Bethlehem Steel Company, Bethlehem PA

Source document Quoted word for word from HAER ARIZ,9-SHLO.V,2-. Not written, edited or summarised by this site.

The Corduroy Creek Bridge and Cedar Canyon Bridge - two al- most identical, steel girder-ribbed arches - were the last links completed on U.S. Highway 60 between Globe and Springerville in and among the last links in the national highway. The two structures are thus historically noteworthy as original com- ponents of a regionally important northeast Arizona route. They are technologically significant for their representation of steel arch design by the state highway department. Visually striking as it spans a picturesque mountain canyon, the Corduroy Creek Bridge is an important, well-preserved example of an uncommon struc- tural type. Report Assembled by: Clayton B. Fraser Fraserdesign Loveland Colorado April Corduroy Creek Bridge HAER No.

AZ-27 page 2 The Historic American Engineering Record [HAER] documentation for the Cor- duroy Creek Bridge was conducted by Fraserdesign of Loveland, Colorado, under contract with the Arizona Department of Transportation. The Department has proposed dismantling the bridge's superstructure and moving it to function as a parallel span to a similar steel arch over nearby Cedar Creek. Tliis recordation is intended to mitigate in part the impact on the bridge by this action. Field recording of both the Corduroy Creek Bridge and the Cedar Canyon Bridge [HAER No. AZ-26] was undertaken in July The research for this project has involved two primary archival sources: the Arizona Department of Transpor- tation and the Arizona State Library, both located in Phoenix.

S tretching between Springerville and Ehrenberg, U.S. Highway 60 has historically formed an important east-west route across central Arizona. The highway functioned as a heavily trafficked ancillary route for U.S. 66 across the northern part of the state, and it provided a vital link between the cities in the Salt River Valley - Phoenix, Tempe, Mesa - with the rest of the state. During the the Arizona Highway Department improved almost all of the route through the state to current highway standards. All, that is, except the stretch between Globe, in the Pinal Mountains, eastward to Springerville, near the state's eastern border. This rugged and remote section represented the last segment of the transcontinental route to be built.

"Practically the entire route of Highway 60, with the exception of that part from Globe to Springerville, or about 130 miles, is completed and in good shape," wrote W.A. Sullivan, an officer of the U.S. Highway 60 Association, in "It is therefore necessary, in order to make U.S. Highway 60 a travelled tourist highway and of use to the country at large, the road from Globe to Springerville by the way of Show Low must have early completion."1 In the late the Arizona Highway Department [AHD] began planning for construc- tion of this segment. Intended to complete the last leg of the transcontinental route, the road would link Springerville, Show Low and other towns on the Mogollin Rim with the town of Globe - and, by extension, with Phoenix.

Department engineers initially consi- dered upgrading the existing regional route, a road built in part by soldiers from Fort Apache.2 But the Rice-McNary Road, as this territorial route was called, was still little more than a wagon trail, despite construction over the previous four years to improve it. "Except for [a] section twenty miles north of White River, the work of building [the Rice- McNary Road] up to the standard highway of today would be the same as constructing a new road," wrote Percy Jones, AHD Chief Locating Engineer, "and the topography of the country traversed is not as well adapted to our present standards of alignment and grades."3 Corduroy Creek Bridge HAER No.

AZ-27 page 3 Rather than upgrade the existing road further, the highway department instead surveyed an all-new route in As explained by Jones in February "The route as it is being planned is the most direct obtainable from the towns of central Arizona, through Globe to the grazing and timber country north of the Rim. That count[r]y supports a considerable population in numerous settlements of which Show Low is a centrally located one. At the town of Springerville, it will connect with U.S.

Route 70, making a route much shorter than the existing ones for travelers entering the state from the middle west on their way to central and southern Arizona to southern California."4 Ironically, part of the route followed another territorial wagon road, the Globe-McMillan route, abandoned some forty years earlier. The proposed highway would branch from the existing road just east of Globe and would extend northwestward past the Apache Mountains to the Salt River. The crossing of the Salt, some 43 miles northwest of Globe, formed a pivotal point in the highway's route.

Here, AHD engineers chose a "nearly perfect" bridge site in a constricted canyon.5 Beyond the Salt River, the route climbed a steep, three-mile incline from the Salt River Canyon to the Flying V Canyon, and from there it continued a long, gradual climb to the Mogollin Rim. The route passed through a natural gap in the rim near Show Low and then veered eastward and eventually southward to Springerville. The Salt River crossing would require the largest bridge along the proposed route, but other major spans would be required to cross Seven Mile Wash, Carrizo Creek, Cedar Canyon and Corduroy Creek.

w, ith the route design completed early in the highway department divided the 130-mile road into a series of shorter sections and began letting contracts for its construction under the umbrella of Federal Aid Project 99. Section A, the first one undertaken, included some of the route's most rugged terrain. Work on it began in mid-June of that year. Using everything from mule teams to trucks, tractors and power shovels, the contractors proceeded through summer rainstorms and sub-zero temperatures in the winter, blasting, filling and grading the road through mountainous terrain on the San Carlos Indian Reservation. Unlike all subsequent sec- tions, this part of the construction was completely isolated and could only be reached by an old 18-mile-long mine road from the town of Hilltop. A.F.

Rath, AHD resident engi- neer in charge of the project, complained: Great difficulty was experienced getting in and out during the winter and spring months. Snowdrifts, mud disgustingly deep under a light blanket of snow, and high centers, made travel impossible at times. Tractors broke trail and brought in supplies when the snow was too deep for trucks to get through and in the spring it was necessary to keep a light tractor on the road constandy in order to pull trucks and cars out of the bogs.6 II Corduroy Creek Bridge | HAER No. AZ-27 I! page 4 The first three miles of this section had to be abandoned because of the mud, but they were eventually picked up in Finally, after eighteen months of brutal construc- tion, Section A was completed near the end of the year.

Comprising the southernmost miles of the route, Section B began just outside of Globe and extended through the Crook National Forest to Apache Peak. This part of the highway also ran through rugged terrain but was far more accessible than Section A. Construction on it advanced more rapidly through completion in July Sections C and D, built in passed through rolling woodlands before making the steep descent into the Salt River Canyon. As construction progressed on the highway, the Depression deepened across the country; soon a premium was placed on employment for the local work force.

Labor-intense hand work was used extensively in lieu of mechanized construction, and the work schedule was changed from the standard eight-hour, five-day shift to two five-hour, six-day shifts with extended furloughs to employ more workers and push construction. "Except for a few, all skilled and unskilled employees were Gila county men," reported Rath. "Labor reports compiled from records show that for a period of 50 weeks the two jobs [Sections C and D] averaged 180 men per day...

The benefits derived from roadwork spread over a large area, if one should care to follow it through from start to finish."7 Using these methods, some 42 miles of highway had been graded between Globe and the Salt River Canyon by October T, he steep rock walls and constricted contour of the Salt River Canyon called for a single-span bridge to carry the roadway high above the river. For this natural crossing, the AHD bridge department engineered a single-span steel arch that flexed against the canyon walls on concrete pedestals. The Salt River Canyon Bridge was an innovative structure - only the third steel arch built for Arizona's highway system. The first had been the three-hinged through arch erected over the Colorado River near Topock, funded by a tripartite agreement between the U.S.

Bureau of Indian Affairs and the states of Arizona and California. Designed in by San Bernadino [California] County Engineer S.A. Sourwine, the 592-foot arch was apparently patterned after the Bellows Falls Arch Bridge in New Hampshire. A breathtakingly bold structure, the Topock Bridge was the8 lightest and longest three-hinged arch in America at the time of its completion in Two years later, the state highway department attempted its own long-span steel arch for a crossing of the Gila River in Greenlee County. State Engineer Thomas Paddock in delineated a 312-foot deck arch to carry the Clifton- Solomonville Road high above the river.

Steel shortages caused by World War I drove the price of the arch well beyond 9the budget, however, and the design was scrapped in favor of a two-span concrete arch. It was several years before the highway department actually built its first steel arch: the 616-foot-span Navajo Bridge over the Colorado River. Completed in the Navajo Bridge was another extraordinary structure - 10as dramatic as it was graceful - that carried the roadway high above the Grand Canyon. Corduroy Creek Bridge HAER No. AZ-27 page 5 With a span length of 162 feet, the Salt River Canyon Bridge was modestly scaled compared with the three other arches. It differed from its predecessors in a more im- portant aspect, however. The other arches all employed three-hinged configurations, with spandrel-braced webs.

The Salt River Canyon Bridge, on the other hand, used riveted steel plates in lieu of the complicated trussing of the spandrel braced arches, and it eliminated the mid-span hinge. The girder-ribbed arch design weighed more than its spandrel-braced counterpart, but it simplified fabrication and erection considerably, saving both time and money. In locations that did not require extensive cantilevering, the girder-ribbed arch proved more economical to build. Its adoption by AHD represented an evolutionary step in bridge engineering. The highway department designated the bridge's construction Section E and in September contracted with the Lee Moor Construction Company of El Paso, Texas, for its fabri- cation and erection. The contractor began immediately on the concrete arch pedestals.

The Salt River Canyon Bridge and its approaches presented multiple curvature problems - "more, in fact, than any bridge so far constructed in the state," according to Rath.11 As a result, its construction went slowly. In January work on the first pylon began. Each 18-ton arch girder was erected in five sections that spring, and in June the immense structure was completed. "From a distance and with its aluminum paint shining in the sunlight, the structure looks more like a delicate piece of filigree than a well designed and constructed highway bridge," rhapsodized Rath. Completion of the Salt River Canyon Bridge marked the symbolic halfway point on the Globe-Springerville Highway.

Although almost 90 miles remained between the bridge and Springerville, once out of the Salt River Canyon most of the path ahead was rela- tively mild compared to the rugged construction in Sections A through D. Rath wrote in July From this point ahead, the construction is all for the future and there is a slight possibility that another Section A may turn up; but I doubt that very much. The next few miles will be heavy construction, as expected. The work will then become easier and less compli- cated, although heavy work is bound to be found in spots.

Whatever its nature may be, it will take two or maybe three hundred men constandy at work daily to finish the next twenty miles within the next year, with the odds in favor of a greater count than that.12 The highway department dubbed the three-mile climb up the other side of the canyon Section F and subsequent segments Sections G through J, as construction progressed steadily northward between and Meanwhile, work had begun on the highway from tne Springerville side under Federal Aid Project Again, AHD divided the con- struction into smaller segments, the first of which extended from the outskirts of Spring- erville. One of the last segments designated - F.A.P. 105-E - involved the erection of the two bridges over Cedar Canyon and Corduroy Creek southwest of Show Low.

$ Corduroy Creek Bridge | HAER No. AZ-27 II page 6 AH. ID'S bridge department designed these structures along similar lines as the Salt River Canyon Bridge, with the main spans comprised of two-hinged, girder-ribbed arches.13 (See Appendix for original construction drawings of the two bridges by the Arizona Highway Department.) The arch spans of the Corduroy Creek and Cedar Canyon bridges are identical. The two structures differ only slightly in their abutments, piers and approach spans, reflective of the slightly different topography. Each bridge spans 180 feet from pin to pin of the end hinges, like the Salt River Canyon Bridge, the arches of the Corduroy Creek and Cedar Canyon structures are comprised of two girder ribs, spaced 21 feet apart to support a 24-foot-wide roadway.

The arches are curved along a constant radius on their centerlines, with a rise from bearing pin to crown centerline.14 Each arch rib bears into a massive concrete pedestal by means of a cast-steel bearing shoe and a 7-inch-diameter pin. The ribs are comprised of a half-inch-thick, 60-inch- deep steel plate, reinforced on top and bottom by built-up flanges that consist of two angles and a flange plate. The web plates are further reinforced by web stiffeners, each made up of two angles and two plates. With such a deep profile, the arch ribs possess a high moment of inertia along their axes. But their relatively narrow flanges leave them vulnerable to lateral loading, necessitating extensive lateral bracing.

A system of built-up struts and diagonal braces joins the two arch ribs rigidly, forming what functions essentially as an arched box beam. Riveted to the upper flanges of the ribs at intervals are 12 WF 40 columns that support the roadway. A 24 WF 94 floor beam is riveted to the top of each column. The floor beams carry four lines of 18 WF 47 stringers, which in turn carry the concrete deck. As on most highway bridges of the time, the configuration and details of the Corduroy Creek and Cedar Canyon bridges have been simplified to the extent possible, with decora- tive treatment limited to the ancillary components. The guardrails are made up of square welded steel tubes, supported by low, curved-top concrete posts.

Concrete bulkheads at the bridges' corners are stepped and flared slightly outward. Mounted on top of each arch pedestal is a decorative vertical pylon comprised of steel channels spaced apart by steel plates. Each pylon extends above, and is integrated with, the guardrail; the channel tops are stepped downward from the center to the edges. The streamlined profile of the arch ribs, combined with the stepped bulkheads and pylons, give the bridge a distinctive Art Moderne character, typical of the AHD detailing for the period.

As an alternative to the steel arches, the Bureau of Public Roads San Francisco office delineated reinforced concrete arches for both crossings in June Like AHD's design, the Bureau's bridges were almost identically configured, each featuring a single, two-rib, open-spandrel arch flanked by concrete girder approaches.15 Each arch spanned 180 feet and had a 135-foot constant radius along its centerline, with a 34-foot rise from spring ! ; Corduroy Creek Bridge 1 HAER No. AZ-27 Ipage 7 line to crown. The arch ribs were doweled into concrete spread footings, and they supported tapered concrete columns, which in turn supported the roadway deck. The only appreciable difference between the two concrete bridges was in the configuration of the approach spans.

What the Bureau's concrete arches saved in superstructural steel over AHD's steel arches, they more than made up in reinforcing steel and concrete. The steel arches would re- quire a total of pounds of structural steel, pounds of reinforcing steel and 768 cubic yards of concrete. The concrete arches, on the other hand, required only pounds of structural steel in the form of bronze bearing plates, but they consumed some pounds of reinforcing steel and cubic yards of concrete. The differ- ence in aggregate weight between the two structural types was significant. The two steel arches, with concrete footings, would weigh a total of approximately16 3.9 million pounds; the concrete arches more than doubled that at 7.8 million pounds.

T, he highway department designated the Corduroy Creek and Cedar Canyon Creek bridges Federal Aid Project 105-E: one of the last segments of high- way construction from Show Low south on U.S. 60. In July the Arizona Highway Commission advertised for proposals to build the two bridges using either the steel or concrete arch designs. Bids for the steel arches were received the following month from four firms: the Pleasant-Hasler Contracting Company and the Packard Construction Com- pany, both of Phoenix, Hagen of Globe, and the Lee Moor Contracting Company of El Paso, Texas. With none of the contractors submitting proposals for the alternate de- sign, the concrete arches were shelved.

Pleasant-Haslets bid of for the two bridges was the lowest of the four proposals; on August 8th the Highway Commis- sion voted unanimously to approve the company's bid.17 Pleasant-Haslets crew began the excavation soon thereafter, working through the remain- der of summer on the bridges' substructures. As another contractor built the highway adjacent to the bridges that fall, the Pleasant-Hasler crew continued work on the concrete abutments and arch pedestals of the structures themselves. The men had the bridges about 20% complete before suspending work due to cold weather at the end of the year. They resumed construction late in March and then operated slowly throughout the following spring and summer.

Using components fabricated by the Bethlehem Steel Company, the steelworkers erected the arch girder ribs in August, extending them from both ends over timber falseworks while a traveler hauled the prefabricated segments onto the bridge and held them in place for riveting. The steel erection proceeded rapidly that month. By the end of September, the project was completed, and the two bridges were opened to traffic.18 The Corduroy Creek and Cedar Canyon Bridges have carried traffic since, with only minor, maintenance-related repairs. II Corduroy Creek Bridge | HAER No. AZ-27 II page 8 Completion of the two bridges marked the last link in U.S. 60 between Globe and Spring- erville, and one of the last links in the national highway.

The structures are thus histori- cally noteworthy as original components of a regionally important northeast Arizona route. The Corduroy Creek and Cedar Canyon bridges are technologically significant for their representation of steel arch design by the state highway department. The Salt River Canyon Bridge marked the first time that AHD used the girder-ribbed arch, followed soon thereafter by these two bridges. Other girder-ribbed arches were later built in the state after World War II, as the highway department adopted this as its standard long-span canyon design.

The 180-foot arches of the Corduroy Creek Bridge seem modest com- pared with the record-setting 800-foot girder arches of the Henry Hudson Bridge in New York, also built in But within the context of Arizona bridge building, the Corduroy Creek Bridge is significant. A much more streamlined structure than its prede- cessors, the Topock Bridge, the Navajo Bridge and the Salt River Canyon Bridge, it repre- sents the prevailing trend in Arizona and the country toward simplification in the detailing of highway bridges. Visually striking as it spans a picturesque mountain canyon, the Corduroy Creek Bridge is an important, well-preserved example of an uncommon structural type. Endnotes J W.A. Sullivan, Secretary-Treasurer of the Arizona Division of the U.S. Highway 60 Association, "U.S.

Highway Arizona Highways, January page 3. In the article Sullivan briefly describes U.S. Highway 60 in Arizona and the country: "Destined to be- come one of the major arterial routes of Arizona when completed, United States Highway 60, running through the central part of the state, virtually bisects the state from east to west. It is one of the few roads in the nation which has been given federal designation before being finished. Its importance in the transcontinental system required recognition before it was completed. Designation has been given to the entire route, approximately four hundred and ten miles long, except a thirty-five mile link from Show Low to Spring- erville in North-eastern Arizona. U.S. Highway 60 starts at one ocean and ends at another.

It is the only transcontinental highway passing through the central part of Arizona, starting at Norfolk, Virginia, thence through Virginia, West Virginia, Kentucky, Illinois, Missouri, Oklahoma, Texas, New Mexico, entering Arizona just east of Springer- ville, Show Low, Globe, Miami, Mesa, Tempe, Phoenix, Wickenburg, leaving Arizona at Ehrenberg and ending at Los Angeles, California. Highway 60 is miles long and is 162 miles shorter than any other transcontinental highway in the United States." 1 Corduroy Creek Bridge | HAER No. AZ-27 i page 9 ^Report of the State Engineer of Arizona, (Phoenix: Arizona State Press, pages 33, 67, 84. 3 Percy Jones, "Location of the New Globe-Springerville Highway Keeps Road at Lower Levels," Arizona Highways, February page 4.

Jones listed the advantages of the all-new route over the existing one, stating: There are three good r[e]asons: First, elevation. This old road goes high. It is above feet in elevation for a considerable distance on the Natanes Plateau, and while this point is not so much higher than the corresponding high spot on the new route, it is for a greater distance, and there is something in the shape of the country that makes the snow fall heavi- er and lie much longer. The writer was in both these places during a recent snow and the difference was quite noticeable. It goes to again six or seven miles below the rim, as does the new route, but reaches on the rim at McNary and from there on up to nearly and then down to at Springerville.

In the past this road has been closed by snow for considerable periods of time. Now, due to higher standards of mainten- ance it is generally kept open, but at a considerable expense, and it is always liable to be closed for short periods. Second - distance. This existing route between the same principal points is 20 miles longer than the new proposed one. While it might be shortened in some places in others it would be lengthened, due to the necessity for development of distance to obtain the present stan- dard rate of grade. Third - Cost of alignment and grade. Except for a few comparatively short sections this existing road is an old wagon road that grew upon the lines of least resistance, between watering places on the way to Ft. Apache.

It has been much improved, noticeably within the last four years to one who knew it before that time. However, except for that section twenty miles north of the White River, the work of building it up to the standard highway of today would be the same as constructing a new road, and the topography of the country traversed is not as well adapted to our present standards of alignment and grades. The final cost of bringing this old road up to present highway standards would probably be equal to or greater than that of building a highway on the direct route and the result would be not as satisfactory. 4 Ibid., page 4. 5 A.F. Rath, "New Bridge Across Salt River and the Country Which It Will Open," Arizona Highways, September pages 15, 17. 6 A.F.

Rath, AHD Resident Engineer, "Highway 60 Moves Northward," Arizona Highways, July page 4. 7 A.F. Rath, "Highway 60 Moves Northward," page 5. I II Corduroy Creek Bridge | HAER No. AZ-27 || page 10 8 David Plowden, Bridges: The Spans of North America (New York: The Viking Press, page "Long-Span Steel-Arch Bridge across Colorado River," Engineering News, 6 April pages For information on the Bellows Falls Bridge, see "The Bellows Falls Highway Bridge," Engineering Record, 5 November pages and "The Bellows Falls Arch Bridge," HAER No.

Proceedings of the Greenlee County Board of Supervisors, 4 March (Book 2, page located at the Greenlee County Courthouse, Clifton, Arizona; Third Biennial Report of the State Engineer, Arizona, (Phoenix: Arizona State Press, pages Fourth Biennial Report of the State Engineer, Arizona (Phoenix: Republican Print Shop, page 60. 10 For more information on the Navajo Bridge, see Clayton B. Fraser, "The Navajo Bridge," HAER No. AZ-28. "A.F. Rath, "New Bridge Across Salt River and the Country Which It Will Open," Arizona Highways, September page 14. ,2 A.F. Rath, "U.S. 60 Moves Northward," page 21. 13 The Arizona Highway Department also designed a third girder-ribbed arch, along with the two bridges on U.S. 60. This third structure was to carry U.S.

Highway 66 over Canyon Padre in Coconino County. The Canyon Padre Bridge, built at the same time as the Cedar and Corduroy bridges, was identical in dimensions to the other two bridges, differing only in minor details. It has since been replaced. H The description of the steel arches is based upon construction drawings produced by the Arizona Highway Department in microfiche copies of which are located at the Arizona Department of Transportation, Phoenix, Arizona. These drawings are repro- duced in the Appendix of this report.

15 The description of the Bureau of Roads concrete arch designs is based upon con- struction drawings produced by the San Francisco office of BOR and dated June Copies of the four-sheet set for the Corduroy Creek Bridge and the six-sheet set for the Cedar Canyon Bridge are located at the Arizona Department of Transportation, Phoenix, Arizona. 16 The weights and measurements for the two bridges are taken from materials schedules on the construction drawings. 17 "Arizona Highway Commission Notes," Arizona Highways, September pages see also, Proceedings of the Arizona State Highway Commission, 8 August located at the Arizona Department of Transportation, Phoenix, Arizona. The bids were each subdivided into 19 components, listed on the following page: I m Corduroy Creek Bridge | HAER No.

AZ-27 || page 11 Item Quantity Description Bidder Hagen Packard Lee Moor Pleasant-Hasler 1 cubic yards Roadway excavation 2 7 cubic yards Drainage excavation 3 cubic yards Slides and overbreakage 4 959 cubic yards Structural excavation 5 sta.

yards Station yard overhaul 6 400 cubic yards imported borrow 7 768 cubic yards Class A concrete 8 pounds Reinforcing steel 9 pounds Structural steel 10 40 lineal feet 42" corrugated metal pipe 11 62 lineal feet 48" corrugated metal pipe 12 13 cubic yards Cement rubble masonry 13 448 lineal feet Road guardrail 14 17 Guide posts 15 12 Right-of-way markers 16 lineal feet Standard wire fence 17 163 lineal feet Crown ditches 18 290 lineal feet Lead seal 19 120 hours Rolling Total Bid 18 "Road Projects under Construction in Arizona," Arizona Highways, September page 20; October page 26; November page 27; December page 31; January page 27; March page 31; April page 25; May page 26; June page 27; July page 26; August page 26; September page 24, October page 30.

19 For more information on the design of the Henry Hudson Bridge, see Stein- man and Gronquist, "Designing the Longest Fixed Steel Arch," Engineering News- Record, 13 August pages $ II Corduroy Creek Bridge | HAER No. AZ-27 !! page 12 Bibliography "Arizona Highway Commission Notes." Arizona Highways. September pages 11- Arizona State Highway Commission Proceedings. Located at Arizona Department of Transportation, Phoenix, Arizona. "The Bellows Falls Highway Bridge." Engineering Record, 5 November pages "Bridge over Cedar Canyon: Globe-Show Low Highway." Construction drawings by U.S. Bureau of Public Roads, San Francisco Office, June Located at the Arizona Department of Transportation, Phoenix, Arizona. "Bridge over Corduroy Creek: Globe-Show Low Highway." Construction drawings by U.S.

Bureau of Public Roads, San Francisco Office, June Located at the Arizona Department of Transportation, Phoenix, Arizona. "Bridge Plans - Special: Cedar Canyon and Corduroy Creek and Canyon Padre Bridges." Construction drawings by Arizona Highway Department, Prints of the draw- ings are located at the Arizona Department of Transportation, Phoenix, Arizona. Davenport, Odessa. "Bridges from the Beginning." Arizona Highways. September pages 4, 28, 31. Dowell, Shelton G. "The Big Business of Road Building." Arizona Highways. September pages 20. Hoffman, R.A. "The Artistic Element in Bridge Design." Arizona Highways. June pages Jones, Percy, Jr. "Location of New Globe-Springerville Highway Keeps Road at Lower Levels." Arizona Highways. February pages 22.

"Long-Span Steel-Arch Bridge across Colorado River." Engineering News, 6 April pages Miller, E.V. "Arizona's New Highway Program." Arizona Highways. August page 6. I ii Corduroy Creek Bridge | HAER No. AZ-27 | page 13 O'Connell, "What Federal Aid Means to the West." Arizona Highways. My pages 18. . "Highways in Review," Arizona Highways. January pages 17. Plowden, David. Bridges: The Spans of North America. New York: The Viking Press, Rath, A.F. "Highway 60 Moves North." Arizona Highways. July pages .. "New Bridge Across Salt River and the Country Which It Will Open." Arizona Highways. September pages "Road Projects under Construction in Arizona." Arizona Highways.

September page 20; October page 26; November page 27; December page 31; January page 27; March page 31; April page 25; May page 26; June page 27; July page 26; August page 26; Septem- ber page 24, October page 30. Steinman, and Gronquist, "Designing the Longest Fixed Steel Arch." Engin- eering News-Record, 13 August pages Sullivan, W.A. "U.S. Highway Arizona Highways. January pages 9 II Corduroy Creek Bridge I HAER No. AZ-27 1| page 14 Appendix On the following pages are the construction drawings for the Corduroy Creek and Cedar Canyon bridges, produced in by the Bridge Division of the Arizona Highway Depart- ment. The drawings reference a third bridge - over Canyon Padre in Coconino County - a similarly designed steel arch built at the same time as these two bridges.

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