To Build a Road
The need for a road from Bridgeport to Pearl Hill was evident even before the Chief Joseph Dam was built between 1950 and 1956. In 1936, the Brewster Herald reported that sentiment was "growing stronger" all over the county for a Pearl Hill road to connect Bridgeport with Grand Coulee (“Road to Dam is Needed”). In 1937, the Grand Coulee Commercial Club passed a resolution calling for "the early completion of the Pearl Hill Road from Bridgeport to the [Grand Coulee] dam" ("Road Is Asked on Pearl Hill"). The club noted that there were three good roads to the Grand Coulee Dam from the south, but "no road of equal quality from the north and west" (“Road Is Asked on Pearl Hill”).
The road was built by 1940, although the current route over Foster Creek was not established until the adjacent Chief Joseph Dam was being built in the early 1950s. At that time, a fill-and-culvert bridge over the Foster Creek channel was built in conjunction with construction of the dam. However, events in 1957 proved that this Foster Creek crossing was insufficient. A Foster Creek flood washed out the fill and subsequently swept "a great amount of Chief Joseph parking lot" into the Columbia River (“Foster Creek Repairs”).Washouts and Construction Troubles
"Foster Creek was supposed to drain out under the fill, but during the highest peak in more than 30 years, according to residents of the area, runoff carried so much silt that it filled up the cracks between the rocks and went over the top," reported the Herald-Reporter in Brewster and Pateros (“Foster Creek Repairs”).
This washout affected the dam's access, since the bridge was just below the westernmost brow of the gigantic concrete dam and served not just Pearl Hill but also areas of the dam complex. For that reason, the Army Corps of Engineers opened bids on July 15, 1958, for work that would include "construction of one concrete bridge and one wooden timber bridge" across the Foster Creek channel ("Foster Creek Repairs"). The former bridge would become the access road to the dam's powerhouse and the latter bridge would become the Chief Joseph Dam Bridge on Pearl Hill Road. The firms of Cherf Brothers, Inc., and Sandkay Contractors, Inc., were the low bidders at $613,386.
The construction process suffered several serious setbacks. A flood on January 11, 1959, washed out one bridge pier "leaving Pearl Hill isolated except by the roadway across Chief Joseph Dam" ("Water Runoff Damages Bridge"). That same month, two construction workers died in separate incidents. One was crushed beneath his bulldozer. The other, Mark A. Miller of Spokane, died when he attempted to remove a hydraulic plug from a piece of heavy machinery. The plug, under high pressure, blew out with great force and struck Miller in the skull.
A Historic and Unusual Bridge
The Chief Joseph Dam Bridge opened in mid-1959, apparently with no formal dedication ceremony. The construction of its main truss, as designed by the U.S. Army Corps of Engineers, was unusual. A Howe truss is "a type of bridge truss having parallel chords, vertical (tension) rods at the panel points, and diagonals forming an X pattern" (Holstine and Hobbs). It was named after William Howe, who patented the design in 1840.
Its significance in this bridge was described by Oscar R. George in the bridge's 2001 nomination form to the National Register of Historic Places: "During this period, the use of wood truss designs, such as the Howe, had long passed from engineering favor. Steel had replaced wood as the material used in bridge trusses. The main span of the Chief Joseph Dam Bridge is the only Howe deck truss remaining on the Washington State Bridge Inventory. ... The structure is an exceptionally significant surviving example of this type of truss. The glued laminated wood members used for the Chief Joseph Dam Bridge truss diagonals are also significant as an early example of the use of this technique"(George).
George went on to describe the engineering details as follows:
"The bridge consists of four timber trestle approach spans (maximum span length of 17 feet) at the northwest end, a 126- foot Howe deck truss main span across the rock-lined channel of Foster Creek, and five timber trestle approach spans (maximum span length 21 feet) at the southeast end. At both ends of the bridge, the approach span connecting to the roadway is supported on a short reinforced concrete abutment. Other approach span supports are short concrete pedestals, with the exception of the spans adjacent to the truss where a larger reinforced concrete column supports one end of the truss and the end of the adjacent approach span. Total length of the bridge is 296 feet 5 and a half inches. The bridge carries one lane of traffic in each direction within a curb-to-curb roadway width of 23 feet.
"The Howe deck truss consists of two 18-foot deep truss sections, spaced 18 feet apart. Each truss has nine, 14-foot panels for a total length of 126 feet. All top and bottom chord, and diagonal members of the truss are of glued, laminated Douglas fir construction. Vertical tension members at each panel point of each truss consist of two steel rods with turnbuckle tightening hardware. The ends of the rods are welded to steel plates that are fastened through steel gusset plates to the wood truss components. Pairs of smaller diameter rods with turnbuckles and similar end connections provide full height transverse cross-ties between the trusses at each panel point, and horizontal transverse cross-ties within each panel at the center of the lower chord. A sawn wood crossbeam, located at each panel point on the lower chord, provides transverse bracing between the trusses. A larger sawn wood crossbeam rests above the upper truss chord at each panel point and supports the longitudinal wood stringers, roadway decking and railing above.
"The bridge's approaches consist of wood post bents, supported both longitudinally and transversely by wood bracing members. The bracing members are fastened at intersecting locations with galvanized steel bolts and/or spikes. Each bent is topped with a wood cap supporting wood stringers, which in turn support the bridging, decking, railing and roadway surface. According to construction drawings, all lumber used in the approaches is 'Coast Region' Douglas fir" (George).
Bridgeport: Its Dam and Bridge
At the time the bridge was built in 1959, Bridgeport had endured several boom-and-bust economic cycles since its incorporation in 1910. In the early years, it had a Columbia River steamboat landing and was an important distribution center for the region's wheat and fruit. The advent of trucking put an end to that role. The most recent boom-and-bust cycle revolved around the construction of the Chief Joseph Dam, The town had a population of 802 in 1950, but swelled to more than 2,000 over the next several years at the height of dam construction.
Then, when construction was completed in 1956, the population dropped back to below 1,000. By 1958 "many business buildings in Bridgeport" were vacant, reported The Spokesman-Review (Mitchell). However, irrigation from the new dam had opened up new land for orchards. Fruit-growing was becoming the most important part of the town's economy. Some of these orchards were accessed via the new, improved Pearl Hill Road. The road also provided recreation access to the new Rufus Woods Lake, the impoundment behind the dam.
The bridge's nomination in 2001 to the National Register of Historic Places was due mainly to the bridge's unusual design elements and its association with the Chief Joseph Dam. It was subsequently determined to be eligible for NRHP listing, and in 2002, the Washington State Historical Preservation Office concurred. However, the bridge was never formally listed in the National Register of Historic Places.
Old and Inadequate
The Chief Joseph Bridge served its purpose for many decades. However, by about 2000, it no longer conformed to modern load-bearing standards. In 2003, Douglas County launched a plan to rehabilitate the bridge in a manner that left the Howe truss and the original bridge piers intact, thus retaining its eligibility as a historic place. The county replaced the old bridge deck with a fiber reinforced polymer (FRP) "plastic" deck, which was lighter and was intended to reduce the weight of the load on the historic truss. The deck was widened from 26 feet to 32 feet and both approach spans were replaced. The bridge’s total length was now 308 feet. This project won several awards as an "innovative solution to a difficult engineering and historic preservation problem" (Cultural Resource Assessment).
The issue appeared to be solved. However, by 2010, engineers discovered that the structure was still insufficient. Some fatigue cracking and other problems had developed. The aging truss still did not have the capacity to carry legal loads. On February 18, 2010, the Quad City Herald ran a headline that read "Chief Joseph Dam Bridge Reduced To A Single Lane" (Walter). The Douglas County engineer announced new weight restrictions and ordered travel restricted to one lane down the middle of the bridge to minimize the loading on each truss. Engineers also determined that the bridge did not meet the region’s current seismic standards.
Douglas County officials came to the conclusion that the bridge would have to be replaced. In 2014, a $4.7 million plan was launched to completely remove the old Chief Joseph Dam Bridge and replace it with a "new 240-foot, single span structure over the Foster Creek channel" which will use "post-tensioned spliced I-girders with a cast-in-place concrete deck" ("Chief Joseph Dam Bridge Replacement"). About $3.7 million came from the Federal Highway Bridge Program and the rest from county funds. A federal budget appropriation request noted that the current bridge was "in danger of becoming impassable by local, emergency, U.S. Army Corps of Engineers personnel and farm-to-market products" and that the new bridge "would meet current design requirements, include two lanes of traffic, and satisfy access needs of the area for decades to come"("Foster Creek Bridge").
Demolition of the old bridge and construction of the new bridge was scheduled to begin in spring of 2015.