The Interlachen Bridge is a reinforced concrete

Reinforced concrete

Reinforced concrete is concrete in which reinforcement bars , reinforcement grids, plates or fibers have been incorporated to strengthen the concrete in tension. It was invented by French gardener Joseph Monier in 1849 and patented in 1867. The term Ferro Concrete refers only to concrete that is...

 arch bridge

Arch bridge

An arch bridge is a bridge with abutments at each end shaped as a curved arch. Arch bridges work by transferring the weight of the bridge and its loads partially into a horizontal thrust restrained by the abutments at either side...

 on William Berry Parkway between Lake Calhoun

Lake Calhoun

Lake Calhoun is the biggest lake in Minneapolis, Minnesota, and part of the city's Chain of Lakes. Surrounded by city park land and circled by bike and walking trails, it is popular for many outdoor activities...

 and Lake Harriet in Minneapolis, Minnesota

Minneapolis, Minnesota

Minneapolis , nicknamed "City of Lakes" and the "Mill City," is the county seat of Hennepin County, the largest city in the U.S. state of Minnesota, and the 48th largest in the United States...

. The bridge crosses the Como-Harriet Streetcar Line

Como-Harriet Streetcar Line

The Como-Harriet Streetcar Line is a heritage streetcar line in Minneapolis, Minnesota which follows original streetcar right-of-way between Lake Harriet and Lake Calhoun and is operated by the Minnesota Streetcar Museum...

, a heritage streetcar line operated by the Minnesota Streetcar Museum

Minnesota Streetcar Museum

The Minnesota Streetcar Museum is a transport museum that operates two heritage streetcar lines in Minneapolis, Minnesota and the western suburb of Excelsior....

 which follows the same right-of-way as the original Twin Cities Rapid Transit line of the same name. The bridge was designed by local builder William S. Hewett

William S. Hewett

William S. Hewett was a major bridge contractor in the Minneapolis area from the 1890s until well into the 20th century. His firm designed and built a number of bridges for the Twin City Rapid Transit Company when it was electrifying and expanding its system around the turn of the 20th...

. The bridge is one of the most significant bridges in Minnesota because it is the earliest known extant concrete bridge with a documented construction date. The bridge was listed on the National Register of Historic Places

National Register of Historic Places

The National Register of Historic Places is the United States government's official list of districts, sites, buildings, structures, and objects deemed worthy of preservation...

 on November 6, 1989, as part of the Reinforced-Concrete Highway Bridges in Minnesota MPS

Reinforced-Concrete Highway Bridges in Minnesota MPS

Reinforced-Concrete Highway Bridges in Minnesota MPS is a Multiple Property Submission of bridges listed on the National Register of Historic Places in Minnesota. The submission includes 20 individual bridges. It also includes the Chicago, Milwaukee and St...

.

The Interlachen Bridge was based on the Melan reinforcing system

Josef Melan

Josef Melan was an Austrian engineer. He is regarded as one of the most important pioneers of reinforced concrete bridge-building at the end of the 19th century. Josef Melan is credited as the inventor of the Melan System, a method for the construction of reinforced bridges...

, invented by Viennese

Vienna

Vienna is the capital and largest city of the Republic of Austria and one of the nine states of Austria. Vienna is Austria's primary city, with a population of about 1.723 million , and is by far the largest city in Austria, as well as its cultural, economic, and political centre...

 engineer Josef Melan

Josef Melan

Josef Melan was an Austrian engineer. He is regarded as one of the most important pioneers of reinforced concrete bridge-building at the end of the 19th century. Josef Melan is credited as the inventor of the Melan System, a method for the construction of reinforced bridges...

and patented in the United States in 1894.