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 north rim has two main viewpoints towards the east, reached by the side road. One is Point Imperial, the highest in the park at an elevation of 8,803 feet, which apart from the canyon, here relatively shallow and less branched, also overlooks large areas of the Painted Desert and the Navajo Reservation. The second is Cape Royal (7,865 feet), perhaps the best of the north rim sites. The cape is 20 miles from AZ 67, right at the end of the road which becomes rather narrow and twisting over the last couple of miles as it runs along a steep sided ridge.