Protection Island, located at the east end of the Strait of Juan de Fuca, is the largest marine bird and mammal breeding site in the state of Washington. Protection Island National Wildlife Refuge was the only such refuge set aside during Ronald Reagan’s presidency. Marine birds and mammals are strongly attracted to this island as a result of unique geological features that provide suitable breeding habitat. No detailed study of its geological features has been undertaken or published, however, despite the fact one of the region’s best exposures of Pleistocene sediments occurs here. Our research team set out to characterize Protection Island’s unique geological features and history. Using standard geological mapping, sampling, palynological, and dating techniques, we are uncovering the island’s past. This past includes at least two glacial advances and interglacial periods characterized by extensive peat bed formation and wooly mammoth, giant beaver, and wild horse occupancy. More recently the island was inundated by a shallow marine bay which supported an extensive clam bed. Today, having risen from the sea, Protection Island serves as Washington’s premiere breeding site for more than 80,000 marine birds and mammals.