When hundreds or thousands of coral polyps build their skeletons close together, they create a calcium carbonate structure that provides habitat and food for a variety of organisms. This is known as a coral reef. Explore a virtual coral reef. More Info - Common Coral Forms; More Info - Fringing Reefs
Arch Cape is an unincorporated community in Clatsop County, Oregon, United States. It is located along the Pacific coast about 4 miles south of Cannon Beach. The Arch Cape post office, established in 1912, has ZIP code 97102. The community was named for a natural arch in the coastal rocks.
Geography[edit] Riddle is about 25 miles (40 km) south of Roseburg and 220 miles (350 km) south of Portland. It lies about 4 miles (6.4 km) west of Oregon Route 99 (Interstate 5) at an elevation of about 700 feet (210 m) above sea level. Cow Creek flows by Riddle before entering the nearby South Umpqua River.