Why Were Bridges Covered?

Most of America's covered bridges were built between 1825 and 1875. By the 1870s, most bridges were covered at the time of construction. The original reason for the cover was to protect the bridge's trusses and decks from snow and rain, preventing decay and rot.

Why were some bridges covered?

The fundamental structural purpose for covering a bridge is to shield the trusses and deck from the elements. Because wooden bridges with exposed superstructures are vulnerable to rot, covering and roofing the bridges protects the trusses from the weather, and so they last longer.

Which state has most covered bridges?

Vermont is home to more than 100 covered bridges, boasting more covered bridges per square mile than any other U.S state. The bridges date from 1820 (the original Pulp Mill Bridge across Otter Creek in Middlebury), with most constructed during the mid and late 19th Century.