72 Microseasons of the Pacific Northwest

By mid-September, Steller sea lion (Eumetopias jubatus) numbers on Pacific Northwest haul-out sites are increasing as summer dispersal gives way to autumn congregation. Steller sea lions are the largest of the eared seals — mature bulls weighing up to 2,400 pounds, with a broad, massive head and mane — and their size and sound make them impossible to miss at known haul-out sites. The Oregon coast holds some of the most accessible sea lion viewing in North America, largely because several iconic sites are reliably occupied year-round and are easily visible from public vantage points. Sea Lion Caves near Florence, Oregon — the largest sea cave in North America — houses a Steller sea lion haul-out visible from an elevator-accessed observation deck 100 feet above sea level. In fall and winter, hundreds of Stellers crowd the cave floor, their bellowing carrying across the headland. Shell Island off Cape Arago near Coos Bay is another major haul-out visible with binoculars from Shore Acres State Park. Three Arch Rocks National Wildlife Refuge near Oceanside, Oregon hosts a mixed colony of Steller and California sea lions (Zalophus californianus) and Common Murres; it is closed to landing but visible from Oceanside Beach. At the Columbia River mouth, up to 1,000–3,000 sea lions — a mix of Stellers and California sea lions — are present in the lower river and adjacent nearshore zone in fall, drawn by concentrations of salmon moving upriver. This large aggregation has been controversial because the sea lions also feed on ESA-listed salmon runs near Bonneville Dam, leading to a complex management program. On the Washington coast north of the Columbia, protection areas around rocky headlands at Olympic Coast National Marine Sanctuary support year-round Steller haul-outs. The contrast in scale between the enormous Steller and the smaller, darker California sea lion at mixed sites is instructive and easy to observe on coastal rocks during the September–March season.