The island has a land area of 1.534 km2 (379.11 acres). It is a federally protected National Wildlife Refuge; boats are not permitted within 200 yards for the safety and health of wildlife on and near the shores. There is only one individual still living on the island not associated with the government, an inholder named Marty Bluewater who has lifetime use of his cabin on the island's southern bluffs. The island also houses a caretaker, a volunteer hired by the Fish and Wildlife department to watch over the island, and take care of its many inhabitants.
Boat trips from nearby Port Townsend, provide ecotourism visits for viewing wildlife from the adjacent waters.
Protection Island is known for its breeding colony of tufted puffin, rhinoceros auklets, and gulls, one of the few such locations south of British Columbia to serve as a home for so many birds. It is on the flyway for many migrating birds. Seals (harbor and elephant), sea lions, orcas, and other cetaceans are often seen nearby.
Spanish explorers were the first Europeans to find the island. In 1790 it was given the name Isla de Carrasco, in honor of Juan Carrasco. It was given its present name by George Vancouver in 1792.