Haystack Rock the U.S. The tallest and probably best known Haystack Rock due to its proximity to Portland is in Tillamook County located off Pacific City and near Cape Kiwanda. It stands above the sea and is the fourth tallest sea stack or off-shore monolith in the world. Haystack Rock in Cannon Beach is accompanied by several smaller rocks known as The Needles. The other Oregon coastal Haystack Rock stands above sea level in Coos County near Bandon. Composed of basalt, Haystack Rock was formed by lava flows emanating from the Blue Mountains and Columbia basin about 15-16 million years ago. The
Trap rock the Green with trap rock quarried from Eli Whitney's quarry, is a particularly colorful example of a red-orange-brown-colored, natural-faced trap rock. It was also used for foundations and railroad beds in the New Haven area. Well-known examples of outcropping trap rock include both intrusive sills and extrusive lava flows. They include the Palisades Sill, a Triassic, 200 Ma diabase intrusion that forms the Palisade along of the Hudson River in New York and New Jersey. Vast areas of trap rock in the form of thick lava flows and other volcanic rocks comprise the Deccan Traps of India and Siberian Traps