Newburgh-Beacon Bridge

…but the newer span is made of “rusting” steel, (believed to be COR-TEN or a similar material although sources are not clear) which surface corrodes to a brown color and does not need painting as corrosion does not go deeper. On November 1, 1980, this second, parallel span, also designed by Modjeski & Masters but constructed by American Bridge Company, was opened to traffic.– Wikipedia