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
Hogg Rock Hogg Rock Hogg Rock is a tuya volcano and lava dome in the Cascade Range of northern Oregon, located close to Santiam Pass. Produced by magma with an intermediate andesite composition, it has steep slopes and thick glassy margins. Hogg Rock exhibits normal magnetic polarity and is probably about 80,000 years old. Hogg Rock lies south of Three Fingered Jack and north of Hayrick Butte, a somewhat larger tuya of similar age and composition. A tuya is a type of subglacial volcano, formed when lava erupts underneath an overlying glacier or ice sheet and then melts through to the surface