 Years of erosion have cut away the soft rocks, forming the valleys, and left the hardest of the ancient rocks relatively untouched on the top of sharp ridges, giving them the appearance of "mountains".The land on which Colton Point State Park sits was once part of the coastline of a shallow sea that covered a great portion of what is now North America.The high mountains to the east of the sea gradually eroded, causing a buildup of sediment made up primarily of clay, sand and gravel.