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.
The towers are how tall? The two towers of the current Tacoma Narrows Bridge rise 467 feet above the piers. How tall is that? By comparison, the Seattle Space Needle is 138 feet taller, measuring 605 feet high. The Statue of Liberty is only 305 feet high, or 162 feet shorter than the Bridge's towers.