During the construction of Highway One 32 bridges were built between Carmel and San Simeon, all designed and constructed under the direction of F. W. Panhorst, Bridge Engineer for the State of California. The first bridge to be completed was a small timber structure across Salmon Creek about 19 miles north of San Simeon which was opened in 1928.
This graceful structure has an arch span of 239 feet and the 497 feet of total deck length carry the roadway 150 feet above the creek. Similar reinforced concrete arches of shorter spans were built across Granite, Garapata and Malpaso Creeks, and a sixth arch bridge consisting of three short arch spans crosses Wildcat Creek about five miles south of Carmel.
The Garrapata Creek Bridge, about thirteen miles south of Carmel, has a150 foot span about 85 feet above the creek plus one 25 foot approach span on the north and four on the south making the total length 285 feet. It was built by Hanrahan Company of San Francisco at a cost of $35,500 and O. R. Bosso was the resident engineer.
Eleven miles south of Carmel the Granite Creek Bridge was built. This bridge has an arch span of 120 feet with two 36 foot approach spans on the north and two 44 foot approach spans on the south for a total length of 288 feet. The arch carried the road more than 100 feet above the creek.
This bridge was built by George J. Ulrich Construction Company of Modesto for $33,700 and the resident engineer was E. E. Sutton.
Two additional concrete arch bridges were built across Malpaso Creek in 1935 and Wildcat Creek in 1933 and another was built across Big Creek in 1938, shortly after the highway was opened. During the construction of the Big Creek Bridge, a storm, reportedly having winds of up to seventy miles per hour, blew down much of the false work in 1937 and it had to be rebuilt.
The Big Creek Bridge is unique because it consists of two arches plus half-arches at each end which are cantilevered and not attached to the earth. The deck carrying the road has swing spans at both ends which are also not attached to the earth. This configuration allows the surrounding earth to move without disturbing the bridge itself. This unusual design was necessary because the earth is very unstable in this area.
An additional arched bridge was built across Dolan Creek but its location required a very long haul for the concrete components. So, the entire bridge was constructed of redwood which was plentiful in the area. It has a span of 514 feet of which 180 feet is carried by the arch itself, 150 feet above the creek. Other large timber bridges were constructed across Lime Creek, Prewitt Creek, Wild Cattle Creek and Torre Canyon while steel bridges were used to span Burns Creek, San Simeon Creek, Pico Creek, Castro Canyon, Mill Creek and Little Pico Creek. All of the timber and steel bridges built between 1928 and 1938 have since been replaced except for the steel bridges over Castro Canyon and Mill Creek. However, the seven concrete arch bridges between Point Sur and Carmel still stand. They were formally evaluated in 1986 and were determined eligible for listing in the National Register of Historic Places. They were automatically included in the California Register of Historic Resources in 1992.