The Cedar Creek Bridge, designated as Clark County's Bridge No. 65 and located at milepost 3.8 on NE Etna Road, was built in 1946, demolished in 2016, and replaced in 2017 by a new bridge. It spans Cedar Creek and is located about 142 feet upstream from the creek's confluence with the Lewis River. The 1946 bridge consisted of a single 75-foot span with a 25-foot cantilever, making for a 100-foot deck. The original bridge was designed by Homer More Hadley (1885-1967), a famed Washington bridge architect. It was a cast-in-place reinforced-concrete bridge of two-cell, single box-girder design. This hollow-box design was innovative for its era, and would later become a common bridge-construction method. However, by 2015 the Cedar Creek Bridge no longer met Clark County's weight-carrying standards and could not be used by logging trucks or other heavy vehicles. The cost of repairs was near the cost of replacement, so the bridge was replaced in March 2017 by a span that met modern standards.
Establishing Cedar Creek
Cedar Creek is within the area originally occupied by the peoples of the Cowlitz and Chinook tribes of the lower Columbia River. Members of other tribes, notably the Taitnapam and Western Klickitat tribes, also occupied areas around the Lewis River.
The first land surveys of the site near the bridge were made in the 1850s. Maps from 1858 and 1863 show land platted into parcels, yet "no ownership is attributed and no improvements are depicted," indicating that the land was probably not settled (Holschuh). Settlers of European descent probably arrived in the 1870s. Cedar Creek was named by these settlers for its many tall cedar trees. The pioneers "earned a living by felling the fragrant cedar trees to produce cedar shakes" (Jones).
One pioneer, James M. "Jim" Forbes (1853-1934), established a homestead near the site of the bridge around 1880. He also built a grocery store "with a dock that allowed boats moving down the Lewis River to obtain groceries for delivery" (Jones). Forbes operated his store until a catastrophic 1894 flood swept the building down the Lewis River.
A Community Legacy
Meanwhile, the community of Etna grew up around the Cedar Creek Grist Mill, which was built in 1876 about two miles upstream of the bridge site. Etna was named by Adam C. "Ad" Reid (1847-1926), from Etna Green, Indiana, who built a sawmill near the grist mill. A post office was established in 1882, but the community failed to grow and the post office was discontinued in 1918. Eventually, not much remained of Etna, although the Cedar Creek Grist Mill was restored to working condition to operate as a museum.
Reid also built a river landing on the Lewis River, not far from the bridge site. Though nothing remains of the small community that briefly sprouted near Reid's river landing, a state boating-access/water-access site was established on the Lewis River just below the mouth of Cedar Creek.
The name Etna lives on mainly because of the community's access road, called Northeast Etna Road. This road served the tiny community during its heyday, and it crossed Cedar Creek at a spot just downstream from the later bridge site. Etna Road was a "minor rural collector" -- a narrow two-lane road (Holschuh).
This old crossing served its purpose well for several decades, but it was configured with a sharp turn at its western approach. In 1946 Clark County embarked on a postwar plan to repair or replace many of its bridges. The county chose to replace the old Cedar Creek crossing with a new concrete bridge, in part because of a desire to eliminate the sharp turn.
A Renowned Builder
The county hired Homer More Hadley to design the Cedar Creek Bridge. Hadley was working for the Portland Cement Association at the time, and he was already recognized for "designing innovative concrete bridges in Washington State, mostly Pierce County, beginning in the mid-1930s" (Ranzetta). Concrete had become an especially popular bridge material in the Northwest because of its clean lines, the availability of Portland cement, and the relative lack of a "steel tradition" compared to the East and Midwest (Holschuh). Concrete bridges introduced "a more modest bridge aesthetic that would minimize their physical presence, particularly in scenic natural settings" (Jones).
At the time, Hadley was known for his work with concrete box-girder bridges. He had been involved with the 1936 design of the Purdy Bridge over Henderson Bay in south Puget Sound, which was "one of the few box-girder bridges within the United States" (Ranzetta). Hadley later went on to design many famous bridges, including the Lake Washington Floating Bridge, later named the Lacey V. Murrow Memorial Bridge.
The Cedar Creek Bridge was one of Hadley's first post-war bridges. He designed it as a "continuous span, two-cell, concrete box girder bridge that consists of a single girder comprised of two contiguous cells" (Holschuh). His concrete hollow-box method of girder construction "utilized less material than traditional slab bridges, since in cellular construction the concrete is poured around hollow box forms ... steel and concrete are placed only at those points where it functions actively under live load" (Holschuh). The hollow concrete boxes were sufficient to support the bridge's "single 75-foot span with a 25-foot cantilever" (Jones).
Building the Bridge
Details about the 1946 construction of the bridge are sparse, but Nieman Company Inc. of Vancouver prepared the falsework plans and may have also been the construction contractor. Shoshana Jones, an architectural historian with engineering firm AECOM, studied the bridge and described how it was built:
"During construction, the concrete was poured into falsework that consisted of approximately six-inch wood boards, as evidenced by the horizontal marks present on the concrete. The bridge piers are hexagonal in section and consist of reinforced concrete poured into solid forms" (Jones).
A 2016 mitigation document, written by Kirk Ranzetta, Jones, and other architectural historians with AECOM, described the bridge in detail:
"The 100-foot-long by 24-foot-wide deck is supported by a single-box girder containing two 4-foot by 8-foot cells. The box is inset approximately 4 feet from each edge of the deck, and the box corners employ chamfered edges to prevent corner stress cracks. The alignment of the adjacent cells creates a flat surface on the box's underside. Approximately 23 feet from the east abutment, the bridge is supported by two 4-foot solid concrete piers ("bents"). The piers are mounted on a 7-foot by 20-foot concrete foundation measuring 4 feet thick. The piers have an octagonal shape that is typically used for stream and river crossings to improve hydraulic movement around the supports. The octagon measures 32 inches across the long face and 9 inches across the short face with a 12-inch chamfer. The piers are set 6 feet apart and are centered below the bridge deck adjacent to the creek bank near the eastern abutment. The east abutment rests on an irregularly laid basalt base that also exhibits a number of repair campaigns consisting of irregularly poured concrete and modern concrete masonry units interspersed with the basalt. At the west abutment, the bridge is supported by a concrete footing block installed on the solid rock slope. The bridge deck is paved in asphalt concrete with a steel guardrail on each side" (Ranzetta).
A Legacy Cast in Place
According to Jones, the bridge is representative of "Washington's first post-war, two-cell, single box, reinforced concrete bridges to feature a continuous span that was 75 feet or more in length ... Washington was only one of four states to use this bridge type prior to the 1950s" (Jones). A 2015 report by Archaeological Services LLC recommended the bridge for listing on the National Register of Historic Places.
In the decades following the construction of the Cedar Creek Bridge, cast-in-place box-girder bridges came to "represent the predominant method of deck construction in the United States" (Holschuh). Yet the Cedar Creek Bridge "represents one of the earliest known examples" and is also "significant as the work of a master engineer" (Holschuh). It was also an "essential expression of his [Hadley's] minimalist design ethic," with its lack of decorative rails and other embellishments, and its efficient use of materials (Ranzetta).
Jones described the innovative nature of the design as follows:
"The hollow box girder concrete bridges erected during this period differ from those erected in the mid to late-1950s by their lack of pre or post-stressing. Pre-stressed concrete is concrete in which reinforcing steel bars are stretched and anchored to compress it and thereby increase its resistance to stress. Pre-stressed box girder bridges represented an important innovation in structural concrete. The pre-stressed concrete bridge was quickly applied to box girder bridge designs and became one of the most commonly used structural designs for road bridges by the 1960s. Therefore, the box girder bridges constructed in Washington prior to the 1950s, such as the Cedar Creek Bridge, were an important precedent for future bridges" (Jones).
The only modification necessary over the years, according to Jones, was the addition of "a metal w-beam guardrail (a guardrail shaped out of steel coil in the shape of a W), supported by pressure-treated wood posts and bolted to the side of the bridge" (Jones).
A New Model
The bridge served its purpose for decades, although by 2015 it had become outdated in significant ways. It could not support heavy loads, including logging trucks, and was one of only two weight-restricted bridges owned by Clark County. A county engineering analysis concluded that "repairing the bridge to correct all structural deficiencies would extend the life of the bridge by only 10 to 25 years" (Clark County Public Works). A new bridge would have a much longer life span, from 75 to 100 years. The cost of building a new bridge would be "close to the cost of repairing all structural deficiencies," so the county decided to remove and replace the bridge (Clark County Public Works).
The construction contractor, Stellar J. Corp., of nearby Woodland, began work in 2016 and demolished the old Cedar Creek Bridge that summer. Construction of a new Cedar Creek Bridge began immediately and was finished in the spring of 2017. The replacement bridge was a "single span, precast concrete T girder bridge approximately 125 feet in length and 32 feet in width" (Ranzetta). The new Cedar Creek Bridge opened to traffic on March 27, 2017.