Man-made fibres are to be distinguished from natural fibres such as silk, cotton, and wool. Natural fibres also consist of polymers (in this case, biologically produced compounds such as cellulose and protein), but they emerge from the textile manufacturing process in a relatively unaltered state. Some man-made fibres, too, are derived from naturally occurring polymers.
Mount Si is located in North Bend, Washington (USA). The climb is 4,167 feet (1,270 meters) and 4 miles from the parking lot to the summit plateau. Vertical elevation change is about 3700 feet and starts at about 700 feet. The route meanders through several different ecosystems as temperatures and average rainfall vary with elevation.
Royal Gorge Bridge, Colorado, United States â Height of 291 m (955 ft). The Royal Gorge Bridge is a tourist attraction within a theme park. The bridge deck crosses the Royal Gorge 955 feet (291 m) above the Arkansas River, and held the record of highest bridge in the world from 1929 until 2001.