Mendocino Redwood Company


Rockport Suspension Bridge



The documents reproduced here give three different perspectives on the Rockport suspension bridge. The first is an article from The Mining and Scientific Press. Published in San Francisco beginning in 1860, this was the first mining journal on the Pacific coast. The article gives a "nuts and bolts" description of the bridge construction in progress. Following the article are excerpts from two letters of D. L. Albert. Albert was the secretary of the Cottaneva Lumber Company. The first letter was addressed to W. E. Guild of Finkbine-Guilld Lumber Company, one of the investors who purchased the assets of the Cottaneva Lumber Company in the mid-1920s; the second letter was addressed to the California Redwood Association. Albert gives a more colorful history of the Rockport suspension bridge. As is often the case with "oral histories", Albert's memory of when the bridge was constructed conflicts a bit with the article in The Mining and Scientific Press. He adds, however, more human details about the man, W. R. Miller, and his "do it yourself" attitude. Bernie Agrons, the last general manager of Rockport Redwood Company before it ceased mill operations in 1957, re-visited Rockport Beach in 2007 and recounted the building of the suspension bridge ( wmv 2.5 MB).



Mining and Scientific Press
30 June 1877


Mr. R. W. Gorrill, Treasurer and Engineer of the Pacific Bridge Co., gives us the following particulars of a new steel wire suspension bridge which he is erecting in Mendocino county for Mr. W. R. MIller. It is located at Cottoneva, on the coast, and extends from the main land to a rocky island where a chute is to be built for shipping lumber.

The distance from center to center of the saddles on the towers is 270 feet. The deflection or fall of the cable is 23 feet, six inches. The cables are built in the same manner as those of the Clifton bridge at Niagara. The steel wire is No. 11 Birmingham gauge, and is protected against rust by immersing in a bath which gives it a fine coat of zinc. There are 11 wires in each strand, seven strands in each one and one-half inch rope, and seven ropes in each cable. The ropes are not twisted together to form the cables, but gathered up every six feet by the suspender bands. Each rope is warranted to bear a strain of 60 tons. Each rope is made fast to an independent anchor-bar, one by three inches in diameter, and forming links 18 feet long, until connection is made with the anchors. The anchors are of cast iron, three and one-half by three feet in surface, weigh 1,000 pounds each, and are placed 14 feet below the surface of the rock.

Great care was taken in securing these anchors in place by means of cross I beams which run under the rock on either side. The lower par of each pit was enlarged so as to form a hemispherical chamber, and the rock-work, set in Portland cement, which is built upon the anchor, is so constructed that the upward strain is transmitted to its sides. The towers are of redwood. There are four posts 10x10 inches, and two 10x12 inches, giving an effective area of 640 square inches to withstand the strain of the cable on the tower. The wooden truss to prevent vertical vibration is eight feet high of of the Howe truss pattern. The 270 feet of the bridge is divided into 45 pannels. The longest suspenders, 44 in number, are of seven-eight-inch steel wire, the 42 shorter ones are of one and one-eight-inch solid iron.

The estimated dead load of the bridge is 1,000 pounds per linear foot; live load, one tone per linear foot; in all, one and one-half tons, or one-fifth of actual breaking load. The bridge will be completed in about 30 days, and promises to be a structure which the builder may well be proud of.

We were shown a portion of an iron bar from the Ashtabula bridge, which was so crystalline in its structure that probably not one-twentieth of its substance had any greater strength than pig iron. This unfavorable condition was undoubtedly produced by the rearrangement of the molecules, produced by the vibration of the bridge under passing trains and changes of temperature. Mr. Gorilla prefers a combination of wood and iron the he truss bridges, as the elasticity of the former saves the iron from the sever strain which is put upon it when all parts are rigid He also insist upon a facto of safety of five in ordinary bridges and six for railways. We hope to illustrate this subject with a good cut of the bride and some of its more important details before long. (Mining and Scientific Press, San Francisco, 30 June 1877, Vol. 34, Number 26, p. 420)


D. L. Albert
C. A. Hooper and Co.,
215 Market St.
San Francisco, CA

7 April 1927

W. E. Guild
Finkbine-Guild Lumber Co.,
Jackson, Mississippi

Dear Mr. Guild:

...Now I am going to give you Mr. W. R. Miller's experience when he built Rockport up in 1875 and 6. He went to the Pacific Bridge Company here in San Francisco for an estimate on that 510 ft. wire suspension bridge at Rockport. After considerable surveying, etc., they gave him an estimate of $100,000 for the bridge only, not including the two approaches you will notice in the photos you have. Another thing, he had less than $50,000 and very little credit, so he told them he would have to give it up if it was going to cost him so much, but that if they would lend him one of their best men for a foreman, he would do it himself.

They told him he could have his pick, so he selected a man by the name of Carl. They went to Rockport, took their measurements, and were back in three weeks. (Remember, they had to go from Petaluma by horseback as there were no wagon roads much farther). They got their materials on a sailing schooner for bridge, sawmill, and a winter's supply of supplies, left here in August 1875, reached Rockport in October. Next month watched for a big high tide and headed the vessel full speed for the beach. Being a flat bottomed vessel with the center load lifted, she went high and dry on the beach where he could unload her. He built the bridge and mill that winter and in July 1876, he launched the vessel, pulled her under his chute, loaded her with lumber and was in San Francisco in August. His bridge, including the two approaches had cost him $25,500. Mr. Miller and Mr. Carl have told me their experiences many times, which were very interesting to listen to. This is what I am leading up to, why bother with contractors and pay them a profit when you can do the work yourself better and save the profit. You will be surprised how fast that wharf work will go if you get a good live crew on your pile driver. It took me 28 days to put the 600 feet in at Hardy Creek. I hope I am not boring you but I cannot help it. The weather is still unsettled; looks like a storm this morning.

Yours truly,

D. L. Albert


D.L. Albert
C. A. Hooper and Co.,
215 Market St.
San Francisco, CA

8 April 1928

California Redwood Association


[At the beginning of the letter, Albert mentions the pictures of the Rockport suspension bridge that he had sent.]

You will note the bridge is a wonderful specimen of engineering, due to the unusual and hazardous difficulties encountered on such a rugged coast.

It was erected in 1875 by Mr. Carl, Engineer of the Pacific Bridge Co., and owned by Mr. W. R. Miller, a pioneer lumber merchant. The bridge was imperative for disposal of lumber from the mill to coastal ships, which, incidentally, cold not get closer than some 150 feet from the rock. Pier construction at that time and particular location would nave amounted to a tremendous figure. The most feasible proposition was a span from the shore line to a large table-top rock, as you may see in the pictures. The selection of materials was carefully considered, as the Engineers knew that the structure would be subjected to extremely severe conditions and hard usage.

Because of it's [sic] phenomenal durability, California Redwood was installed in all the frame construction. Fourteen 1-3/4" galvanized steel cables were stressed over four towers, each built of six 14'X14' Redwood timbers. In 1886, W. R. Miller sold out to the Cottoneva Lumber Company and up to 1900 the bridge was in constant use until the mill was destroyed by fire that year. From 1900 to 1925, it was entirely unattended and no care was taken of it whatsoever. During the summer of 1925 some careless people left fire near the bridge which destroyed the shore end. However, the Redwood towers on the ocean end are still standing. I have sent you a piece of one of these timbers, and you may see for yourself that after 50 years service, the wood is in as good a condition as the day it was incorporated in the structure.

This, I believe, is a remarkable example in durability of this wonder-wood, and I feel justified in stating, that I cannot think of a more durable and serviceable species to use for wood construction that will be exposed to the most trying conditions possible, as California Redwood.

Yours truly,

D.L. Albert


Author: DMS


Photo Credit

Rockport suspension bridge and rails. Robert J. Lee Collection, Ukiah, Ca.

Primary Source

Rockport Redwood Company Records, BANC MSS 70/184 c, The Bancroft Library (Berkeley, California).

Secondary Source

Mining and Scientific Press (San Francisco), 30 June 1877, Vol. 34, Number 26, p. 420.


Video interview of Bernie Agrons, Rockport Beach, 6 May 2007, conducted by Doris M. Schoenhoff


 Mendocino Redwood Company - Ukiah, California