Crown Point Viaduct

Crown Point Viaduct

Columbia River Gorge, Crown Point Viaduct Wall in foreground, ca. 1920

Columbia River Gorge, Crown Point Viaduct Wall in foreground, ca. 1920


East Approach to Crown Point, Viaduct in Background, ca. 1920

East Approach to Crown Point, Viaduct in Background, ca. 1920


Vista House and Crown Point Viaduct, ca. 1990

Vista House and Crown Point Viaduct, ca. 1990

Crown Point Viaduct, ca. 1990.

Crown Point Viaduct, ca. 1990.

Location

Encircling the site of Vista House, a masonry public comfort station, on the Historic Columbia River Highway, beginning at milepost 24.

Date of Construction

1914

Engineer

Samuel C. Lancaster, Consulting Engineer to Multnomah County and Assistant State Highway Engineer, Oregon State Highway Commission.

Builder

Pacific Bridge Company, Portland; Robert Lee Ringer, subcontractor

Owner

Oregon Department of Transportation

Present Use

Vehicular and pedestrian traffic

Significance

A half-viaduct designed to carry pedestrians around the outer edge of a spiral section of roadway around the top of a 725′ promontory on the Historic Columbia River Highway. Ingenious use of reinforced-concrete and rubble masonry to create an aesthetically pleasing structure.

Crown Point Viaduct

Chanticleer Inn, 22 miles east of downtown Portland in rural Multnomah County, was a frequent gathering place for the Historic Columbia River Highway’s promoters. In 1912, it was as far as anyone could safely drive from Portland on the county road system before encountering the maze of steep goat trails and skidroads that passed through the Gorge. The innkeepers provided hearty chicken or game dinners served in a comfortable setting at an elevation of nearly 900′. Diners overlooking the Columbia River were regularly treated to beautiful sunsets on the Gorge. After one such visit to Chanticleer, Lancaster was impassioned to write that:

“Standing here I realized the magnitude of my task and the splendid opportunity presented. Instinctively there came a prayer for strong men and that we might have sense enough to do the thing in the right way . . . so as not to mar what God had put there. … In that [gorge] to the east were hidden waterfalls and mountain crags, dark wooded, fernclad caves, and all else that a wise Creater [sic] chose to make for the pleasure and enjoyment of the children of men.”

In September 1913, Lancaster began surveying for the highway between Chanticleer Inn and Multnomah Falls, 8 miles east. Lancaster’s “‘first order of business was to find the beauty spots, or those points where the most beautiful things along the line might be seen to the best advantage, and if possible to locate the road in such a way as to reach them.'” The first of these was Thor’s Heights, named after the Norse god of thunder, a 725’ promontory less than 2 miles east of Chanticleer Inn and positioned such that one could see both up and down the Columbia River for nearly 40 miles. He originally planned to locate the highway at water-level, near the river, and around the base of Thor’s Heights. However here, and throughout the gorge the Oregon-Washington Railroad and Navigation Company main line right-of-way took all the available space between the Columbia and nearby basalt formations. Because Lancaster saw the promontory as one of his beauty spots he included it on his alignment. He designed a circular road cut and sidewalk viaduct to spiral around the cliff top before making a decent to several waterfalls in the following ten miles. The owners of Thor’s Heights gave right-of-way to the county and nearly one acre of ground on top of the rock for a public park to be under Portland’s jurisdiction.

In 1915 Lancaster referred to Thor’s Heights as “Thor’s Crown,” but at some time Thor’s Heights was renamed “Crown Point.” The name was probably altered when the viaduct was completed; its ring of lamp standards encircling the cliff top gave it the appearance of a royal crown. One Sunset Magazine correspondent wrote that when the Crown Point Viaduct was illuminated at night with dozens of “electroliers,” the promontory “looks for all the world like a huge jewel-set crown.” To Lancaster, the old name Thor’s Crown inspired him for his plan for a memorial for Crown Point. He believed, “The silent dignity of the pavilion, with its outline against the sky, will recall the ancient and mystic Thor’s Crown, which the point was originally named.” He proposed constructing a building of the Tudor Gothic-style on the horseshoe-shaped space within the viaduct as an observatory for travelers, as a memorial to the Oregon Pioneers, and as a public comfort station. He suggested it be known as “Vista House.” Over fifty prominent Portland business and civic leaders, including Multnomah County Roadmaster John B. Yeon, retired lumberman and hotel owner Simon Benson, and Oregronian newspaper publisher H. L. Pittock, approved of Lancaster’s idea in October 1915 and formed the Vista House Association to oversee the building’s construction.”

In May 1916, the Multnomah County Board of County Commissioners was impressed by the idea and appropriated $12,000 from the county emergency fund to begin construction of Vista House. Meanwhile, the HCRH was formally dedicated on June 8, 1916. Both Crown Point and Multnomah Falls hosted the event, with Crown Point being the site where a United States flag was unfurled at the touch of a button by President Woodrow Wilson at the White House in Washington, D.C.

Prominent Portland architect Edgar M. Lazarus, who was also a member of the Vista House Association, was selected as the structure’s designer. He previously completed plans for several large houses in northwest Portland, along with several other structures. These included a 1903 addition to the U.S. Post Office and Court House, along with an under-the-sidewalk public comfort station at the nearby corner of Southwest Sixth and Yamhill streets. For Crown Point, Lazarus designed a reinforced concrete domed octagonal building with basement restroom facilities, women’s lounge and caretaker’s quarters; a main floor visitor center; and an outdoor observation balcony. The building was sheathed in sandstone blocks and capped with a tile roof. Concentric circles of stairs ran from grade to the main floor entrances. Vista House was completed in May 1918, nearly two years after the formal highway dedication, and nearly $80,000 over original cost estimates at $100,000.

In the fall of 1915, an entrepreneur named R. T. Dabney, who owned much of the land adjoining the top of Crown Point, proposed building a hotel at the cliff’s edge, to the north of the viaduct. Portland Oregonian reporter Marshall N. Dana wrote that “in structure it will partake of the solidity of the cliffs. In architecture and attitude it will command the view like a castle on the Rhine.” Dabney planned for a Tudor Gothic-style structure visible from the railroad and the river below, but inconspicuous from Vista House. Travelers could reach it by automobile on the Historic Columbia River Highway and by an inclined railway from a railroad siding below. He even sought Lancaster’s advice, and brought Lazarus in to render plans, with the hope of opening his hotel by tourist season in 1916. One “giant feature” that Dabney envisioned was a pipe organ to be known as the “Voice of the Gorge,” along with an echo organ placed a half a mile away and under such wind pressure that its tones might be heard for miles up and down the river. The main organ’s five manuals and many ranks of pipes could “produce something to interpret the voice of nature and those subtle reflexes of which nature is so full of.” The echo organ could produce the “voice of the firs,” which imitated wind blowing through trees, or the “tempest,” which could reproduce “the lowest moaning of the wind to the most awful shriek that ever came through the gorge.” Finally, another would “imitate the patter of rain.” This fanciful proposal remained unrealized; Dabney never built his hotel or the organ. However, Lancaster’s dream of a pavilion of honor had come true.

Design and Description
Crown Point Viaduct – reinforced-concrete

The viaduct’s purpose was to convey motor vehicles around the promontory. This was to be accomplished in as close a curve as possible, without being any tighter than the minimum 100′ turning radius that Lancaster and others set out when they began designing the Historic Columbia River Highway. From the point, vehicles traveled east down a series of “Figure Eight” curves from Crown Point’s elevation of 725′ to a crossing of Latourell Creek at 200′, or west along a section of the Historic Columbia River Highway that gained over 100′ in less than two miles before it reached Chanticleer Inn. The viaduct and road cut “fits the top of this rock like a hat rim,” wrote one columnist, as it circles through 225° with beginning and ending points reading at approximately southwest and southeast on a compass. It had a turning radius of 110′.

The viaduct provided a means for adding a sidewalk, parapet wall and light poles onto the outer edge of the roadway. The road was founded on the point itself, placed around it on cuts and fills, but the viaduct’s substructure did serve the roadway by providing retaining walls. The retaining walls were constructed with twenty-eight 20′-0″ reinforced-concrete slab spans resting on outer reinforced-concrete columns and inner concrete footings. The slabs form portions of a 7′ sidewalk, and support a 4′-0″ reinforced-concrete parapet wall. Total length of the viaduct is 560′. Originally, twenty-nine reinforced concrete lamp standards with spherical globes ran at regular intervals along the viaduct’s concrete parapet wall. They were placed on top of the concrete support columns, which were engaged with the parapet wall. One of the state highway department’s design engineers remarked about the railing and lights that, “at night there will be presented to the view of the travelers, who hurry by on the trans-continental trains and boats, far below, a halo light suggesting the name which this view point carries.”

The viaduct has a relatively straightforward substructure, only complicated by the terrain. In its most basic form, it consists of the outer 12″ x 12″ columns with footings, and a set of inner footings resting on the uphill ledge. As the viaduct spirals around the point from west to east, it drops in elevation. At the same time, the outer columns lengthen as land below falls away. Retaining walls, in which the viaduct’s inner footing were anchored, vary between vertical reinforced-concrete structures and dry masonry batter structures. Finally, on the portions where outer columns and concrete retaining walls were used, 12″ X 12″ inclined struts were inserted between the base of the outer column and a buttress curb of the wall. These struts added stability to the structure and are similar to those used on the West and East Multnomah Falls viaducts less than 10 miles to the east. Nevertheless, they did not appear on portions of the structure where the batter walls were used, even when the columns were the longest, at 10′ to 15′.

Crown Point Viaduct – masonry

On his trip to Europe with Hill and others in 1908, Lancaster marveled at the extensive use of masonry walls, especially in Switzerland and Italy. Unsubstantiated stories suggest that he imported Italian masons to construct the many miles of basalt guard rails, guard walls, and retaining walls seen throughout the Historic Columbia River Highway. Masons with Italian surnames built the structures, but whether they came from Italy to work on the road has not been proven. The Crown Point Viaduct site includes many feet of masonry structures. A curved masonry guard rail runs for 225° of a circle between Vista House and the roadway from the southwest to the southeast. It originally consisted of a 30″-tall random rubble slip-form wall, 12″-wide with a 14″-wide screeded concrete cap. Parabolic arched drainage openings were placed regularly at curb level. Even though these cutouts have no real purpose (the curb along Vista House’s parking lot directs rainwater runoff), they echo a common masonry motif seen throughout the HCRH. The wall was pierced by a staircase north of Vista House that provides access to the building’s lower level and to the roadway as it makes its descent Dry masonry random rubble walls at a batter of 45° encircle Crown Point and retain the hillside between the masonry guard rail and the roadway. These walls are similar to those found under the viaduct that hold the roadway.

Repair and Maintenance

To the untrained eye. Crown Point Viaduct looks as if it remains unchanged since its completion in 1915. In reality, it includes many replacement structures which are sympathetic or unsympathetic to the original construction. The masonry guard rail at the top of the upper embankment retaining wall has received some major modifications. Only the portion west of the north-facing staircase is original. The eastern portion was rebuilt in the mid-1930s because it failed. Its replacement, though in sympathy with the extant western portion, is different. Instead of replicating the original wall with slip-formed grouted random rubble on both elevations, masons chose only to use the random pattern on the outer elevation, and substituted ashlar or rectangular-cut basalt blocks for the interior of the curve (or the part facing Vista House). At its beginning point, where the steps lead northward and down to the spiraling roadway, the bannister was squared off, rather than being rounded and sculpted as was the original. In addition, masons placed ashlar posts at regular intervals along the new wall, and within these, they probably add reinforcement to prevent the wall from again bowing outward and possibly collapsing. Beyond the original semicircular portion of masonry guard walls, on the eastern end, a later wall of random rubble, and of smaller dimensions, was added to extend the original structure south and east.

The dry masonry stone embankment, rising at 45° from the spiraling roadway below, is generally in good condition, though it has received inappropriate patching with mortar. This effectively traps moisture behind the wall and prevents it from percolating to the surface and could lead to extraordinary pressures which could “blow out” the wall. A dry masonry retaining wall was added to the site in the 1980s, just to the south and west of the viaduct’s western beginning point. It serves as an end point for an additional parking area southwest of Vista House and the viaduct. Even though it is sympathetic to the design of other dry masonry retaining walls, it is a new structure and did not replace a previous wall.

The north-facing concrete staircase, immediately north of Vista House, has received very bad treatment in the last 4 0 years. A 1955 heating system for Vista House required installing a furnace flue in the staircase landing. The masonry guard wall was extended across the top of the stairs to prevent visitor access to the area around the flue. Both obstructions were removed in the 1980s as part of a renewed interest in preserving Vista House and the surrounding structures.

The concrete sidewalk and parapet railings on the Crown Point Viaduct have required continual maintenance. The absence of asphaltic felt expansion joints at critical points has created severe cracking of slabs Joints are not continuous. For example, while deck slabs may have expansion joint separating them, there were no provisions made for expansion nearby at the curb nor along the parapet wall.

Below the deck, reinforcing bar corrosion has spalled the underside of the sidewalk slabs. Some portions of the concrete retaining wall have been undercut and appear to be resting on thin air. There is also some inappropriate patching of the dry masonry wall with mortared joints. Here as elsewhere, a buildup of moisture could cause the wall to fail. The reinforced concrete viaduct columns appear in good shape.

Originally, the viaduct had 29 reinforced-concrete lamp standards topped with delicate spherical glass fixtures. They appeared like miniature global models of Earth with metal bands on them arranged like longitudinal and equatorial lines. There was one lamp post resting on top of each concrete outer support column between girder spans. This lamp design diverged greatly from those shown on original plans, which called for ornate brass fixtures on topping the columns. They had simple globes with a center one flanked by two others of like size, but a slightly lower and on ornate brass arms. Nevertheless, from early on, it was evident that the original glass spheres were not durable. Crown Point’s severe winter weather, with winds approaching 100 miles per hour, accompanied by rain, sleet, and snow, were more than they could endure. They often collected ice during the day, only to shatter at night when illuminated. Those that the winter elements did not wreck, vandals destroyed. It appears that by either the mid-1920s or mid-1930s, half of the lamp poles were removed and those left were fitted with new polygonal Gothicstyle cast brass lighting fixtures. In 1979, the original posts were replaced and have received continuing maintenance with surface applications of cement grout. At the same time, local Benson High School students recast the 1920s/1930s lamp fixtures at the school foundry.

Appendix – Viaducts

Viaducts, often bridges resting on a series of narrow reinforced-concrete piers or bents and carrying a road over a valley, cleft, or concavity, have many forms on the Historic Columbia River Highway. They were used primarily to keep construction costs down when alternative road alignments meant expensive grading or “developing distance” by building extra lengths of road to maintain a grade no greater that 5 percent.

Full Viaducts
Mitchell Point Viaduct

At the west approach to Mitchell Point Tunnel engineers designed a 193′-0″ reinforced-concrete slab and girder type viaduct. The viaduct was supported on sets of columns 15′-6″ apart center-to-center, and 32′-0″ longitudinally to carry the Historic Columbia River Highway from a cliff cut over a talus slope concavity to a tunnel portal. Locating this structure was difficult because the talus slope below over was unstable, making it hard for crews to locate firm footings for bents. Excavations were done by hand and proved very time consuming.

The Mitchell Point Viaduct was a fairly nondescript structure with precast railing panels. Yet it was functional with an understated aesthetic component that prepared motorists for entering the Mitchell Point Tunnel, which some have called the most inspiring part of the Historic Columbia River Highway. The tunnel and viaduct were completed in 1915. A new water-grade route for U.S. 30, mostly built on fill from river dredging, was completed from Portland to The Dalles by the early 1950s. Oregon highway officials closed Mitchell Point Tunnel and consequently the adjoining viaduct in 1953 and backfilled the tunnel in an attempt to stabilize the basalt formations of Mitchell Point. In 1966, as part of a widening project to upgrade the water-level route to a four-lane interstate highway, a large portion of Mitchell Point, including the tunnel and viaduct, were destroyed.

West and East Multnomah Falls viaducts

The road alignment immediately west and east of Multnomah Falls runs between the Oregon-Washington Railroad and Navigation Company main line and a steep mountainside. There were no realistic alternate alignments for the Historic Columbia River Highway here because the railroad tracks ran next to the river’s edge. Engineers avoided marring the natural landscape wherever possible and often saw the best solution for creating satisfactory alignments was to construct the road on fill behind solid dry masonry retaining walls. However, for the West and East Multnomah Falls viaducts they needed to bridge very steep and unstable slopes that were susceptible to slide action. Even minimal cutting and filling at the toe of these mountainsides, held together by underbrush and timber, might cause rock and debris avalanches to cover the roadway and, probably more importantly, block the railroad’s main line.

The West Multnomah Falls Viaduct is 400′ in length and consists of twenty 20′ reinforced-concrete slab spans. The deck is supported by two parallel rows of 16″-square columns, or bents, 17′-6″ apart. The corners were chamfered, both for aesthetic purposes and to eliminate sharp corners prone to chipping. This shape also facilitated removing the formwork. Roadway width is about 18′. The design engineer K. P. Billner included inclined struts between the footings of the inside and outside piers because he saw a need to guard against settling of the upper columns and to achieve greater structural stability. With confidence he believed that they could “carry the weight of the structure.” The East Multnomah Falls Viaduct is identical to the West Multnomah Falls Viaduct, except that it is 860′. Both were completed in 1914.

Half-Viaducts

Engineers designed half-viaducts for several locations on the highway also to skirt hillsides. They were constructed much like viaducts with unequal-length columns, except that the inside bents consisted only of footings and the inside elevations were anchored into the hillsides or masonry walls. Because of the half-viaducts’ inconspicuous design, motorists often did not realize that they were not traveling on regular highway pavement with masonry guard rails.

Toothrock and Eagle Creek Viaducts

High above the river, Toothrock and Eagle Creek Viaducts (HAER No. OR-36-N) (224») carried the highway around Toothrock, a tall basalt cliff, high above the river before dropping down to Eagle Creek. Their designs differ only in their railing treatment, where Toothrock Viaduct uses a concrete spindle and cap design. Eagle Creek viaduct uses a masonry rail and concrete cap design. Their purpose was to minimize costs but create sound structures with an aesthetic component. Completed in 1915, they were abandoned in 1937 at the completion of Toothrock Tunnel and a new water-level realignment of the trunk route near Bonneville Dam.

Ruthton Point Viaduct

Ruthton Point Viaduct, completed in 1918, is a 50′ structure consisting of three reinforced-concrete deck girder spans (20′, 20′, and 10′) carrying the highway near a promontory west of Hood River, It used a simple standardized concrete railing panel and cap. It was bypassed when the new water-level route for U.S. 30 was completed in the early 1950s. Since then it fell into disrepair, taut in the early 1990s, as part of an Oregon Department of Transportation restoration project on the HCRH, Ruthton Point Viaduct was reconstructed to be part of a pedestrian and bicycle accessible trail along once abandoned sections of the route.

Rock Slide Viaduct

The 34′ Rock Slide Viaduct, completed in 1920, lies a short distance west of the Mosier Twin Tunnels. The viaduct was probably necessary, rather than a dry masonry retaining wall, because of the unstable nature of the basalt slope. The viaduct’s uninterrupted roadway surface and the continuous arched rubble parapet railing made it difficult for travelers to identify the structure from the road. In the late 194 0s and early 1950s, the Oregon State Highway Department completed a water-level route for U.S. 30 along the Columbia River. In 1953, it finished the section between Hood River and Hosier and closed the Mosier Twin Tunnels. The portion of the HCRH from Hood River to the tunnels’ west approach, including Rock Slide Viaduct, became part of Hood River County’s extensive road system.

Excerpted from Historic American Engineering Record, Crown Point Viaduct, HAER 0R-36-c.
Historian: Robert W. Hadlow, Ph.D., September 1995
Transmitted by Lisa M. Pfueller, September 1996