72 Microseasons of the Pacific Northwest

Steller sea lions (Eumetopias jubatus) — the largest of the world's eared seals, with males exceeding 2,500 pounds — have become a year-round presence at Bonneville Dam on the lower Columbia River. First recorded at the dam in 2003, they are now present for roughly 11 months annually, arriving in greatest numbers from December through April to exploit steelhead and Chinook salmon funneling through the tailrace. Dozens of animals, a mixture of Stellers and California sea lions, haul out on floating structures in the tailrace daily. The Bradford Island Visitor Center at Bonneville Dam, located along SR-14 in the Columbia River Gorge National Scenic Area, offers a fish viewing window and an upstream deck where these massive mammals can be observed from close range. Stellers are notably larger and tawny-blonde compared to the smaller, darker brown California sea lions. Their guttural roars, barks, and growls echo off the basalt walls of the gorge. Peak activity at the dam coincides with the arrival of spring Chinook and winter steelhead runs, making this an exceptional convergence of large fish and large marine mammals far inland. The presence of Steller sea lions 150 miles from the ocean in late winter is a striking reminder of the Columbia River's historical richness. Wildlife managers conduct monitoring from the dam facilities, and viewing platforms are designed to accommodate public observation. For those combining a visit to the area, the adjacent sternwheeler replica and fish ladder windows at the visitor center provide additional context for the entire Columbia River salmon system that draws these giants inland each winter.