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
Lava Creek Tuff Lava Creek Tuff The Lava Creek Tuff is a tuff formation in Wyoming, Montana and Idaho, United States, created during the Lava Creek eruption around 630,000 years ago, which formed the Yellowstone Caldera. The Lava Creek Tuff is distributed in a radial pattern around the caldera and is formed of of ignimbrites. The tuff has been exposed by erosion at Tuff Cliff along the Gibbon River. Lava Creek Tuff ranges in color from light gray to pale red in some locales. Rock texture of the tuff ranges from fine-grained to aphanitic and is densely welded. The maximum thickness of the