Simpson Reef & Shell Island Overlook: Oregon Coast Marine Life

Simpson Reef and Shell Island Overlook is located just off Scenic Cape Arago Highway within the boundaries of Cape Arago State Park. A part of the Oregon Islands National Wildlife Refuge, Simpson Reef, Shell Island, and the surrounding rocks and reefs are the largest haul-out for marine mammals on the Oregon Coast. Due to the reefs and islands being breeding and resting areas for sea lions, seals, and seabirds, they are closed to public access at all times.

A gradual slope of offshore rocks, reefs, and sandy beaches, Simpson Reef is a favorite resort location for seals and sea lions to haul out of the ocean. Northern Elephant Seals, Harbor Seals, Northern Sea Lions, and California Sea Lions haul out to give birth, nurse pups, breed, or simply to rest and sleep.

Simpson Reef and Shell Island are also visible from Shore Acres State Park and along hiking trails between Shore Acres and Cape Arago. Constructed in 2003 at the end of Cape Arago Highway (North Cape Arago State Park), Simpson Reef Overlook offers a great opportunity to view and photograph marine wildlife in their natural habitats.

Northern Elephant Seals

Northern Elephant Seals (which lack a visible ear flap) are the deepest-diving and largest sea mammals. Males can weigh over 5,000 pounds (over 2,200 kilograms) and are up to 13 feet (4 meters) in length. Females weigh less than 1,000 pounds. They are gray or tan without any spots.

Shell Island is the northernmost breeding site of elephant seals on the Pacific Coast. They are winter breeders, and pups can't survive in the water for 8-10 weeks after birth. Because of winter storms, northern elephant seals' pups rarely survive on Simpson Reef.

Harbor Seals

Harbor Seals (lack a visible ear flap) are the smallest seals at Cape Arago. Mature males and females are similar in size, ranging from 150 to 300 pounds (70-136 kilograms) and 5-6 feet (1.5-1.8 meters) long. Their skin color varies from light to dark grey with dark spots.

At Cape Arago, Harbor Seals give birth in April and May and nurse their pups for three weeks. Young harbor seals can swim at birth and have a high chance of surviving in severe ocean conditions.

Steller or Northern Sea Lions

Steller or Northern Sea Lions are the sea lion family. Mature males can weigh up to 2,400 pounds (over 1,000 kilograms) and are about 10 feet (3 meters) long. Females are 700 pounds (317 kilograms) and 7-8 feet (2-2.4 meters) in length.

Sea Lions have visible ear flaps and can turn their hind flippers under their bodies, allowing them to walk on land. They are yellowish-brown with dark brown flippers and have a deep, loud roar.

Steller Sea Lions are summer breeders, but they don't breed at Cape Arago. They use rocks at Simpson Reef and Shell Island as haul-out sites. One of the breeding sites in Oregon is Sea Lion Caves in Florence.

California Sea Lions

California Sea Lions are easily identified by their noisy barking. Only males migrate to Cape Arago during late summer and fall. Females and their pups remain in California. Mature males weigh over 500-700 pounds (227-318 kilograms) and grow to 8 feet (2.4 meters) long. Females weigh 200 pounds (90.1 kilograms) and are 6.5 feet (2 meters) in length. They are brown in color, and males with age develop a light tuft of fur on their heads.

California Sea Lions breed in California in the summer months. After breeding, males migrate north and use the Cape Arago area as a haul-out site from late summer to spring. Females with pups remain in California.