Fort Stevens began in 1863 as a crude earthwork battery on the south shore of the Columbia River's mouth, built during the Civil War to defend against a British attack that, in truth, seemed unlikely but not impossible. The Pig War of 1859 had brought Britain and the United States to the brink of conflict over the San Juan Islands, and tensions in the Pacific Northwest ran higher than most Americans today realize. Originally called the Fort at Point Adams, it was renamed in 1865 for Isaac I. Stevens, the former territorial governor of Washington who had been killed at the Battle of Chantilly in 1862. Fort Stevens anchored a three-fort harbor defense system at the Columbia's mouth, joined by Fort Canby and Fort Columbia on the Washington shore. Together they formed a triangle of firepower meant to ensure that no hostile fleet could push upriver.

Between the world wars, Fort Stevens took on a quieter but more sensitive mission. In 1932, the Navy co-located a secret radio intercept station at the fort, designated Station S, staffed by specially trained radiomen from the so-called On-the-Roof-Gang -- codebreakers who had learned their craft in a classroom atop the Navy Department building in Washington, D.C. Their job was to listen to Japanese naval coded messages, work that would prove prescient within a decade. By 1939, the Navy relocated Station S to Fort Ward on Bainbridge Island, where intercept conditions were better, but the fort's brief chapter in signals intelligence hints at a military landscape far more complex than its earthwork batteries suggest.

The I-25's shelling on June 21-22, 1942, lasted only minutes. The submarine's 14-centimeter deck gun was a modest weapon, and the crew fired blindly toward shore in the dark. Seventeen rounds hit sand, brush, and the unfortunate baseball field. No one was injured. The decision not to return fire was tactical -- the fort's gun positions were camouflaged, and revealing them to protect a baseball diamond made no sense. But the psychological impact rippled far beyond Clatsop County. West Coast residents, already anxious after Pearl Harbor and the internment of Japanese Americans, now had proof that enemy vessels were operating just offshore. The I-25 would return to Oregon waters later that year, launching an incendiary bombing mission from its floatplane over the forests near Brookings -- the only aerial bombing of the contiguous United States during the war.

Fort Stevens was decommissioned in 1947. Its guns were removed, its buildings auctioned off, and its grounds transferred to the Army Corps of Engineers before finally reaching the Oregon Parks and Recreation Department in 1975. Today the 3,700-acre state park draws nearly 1.2 million visitors a year, making it one of the busiest parks in Oregon's system. Underground tours wind through the old military batteries, and Battery Russell still stands open to the wind, its concrete walls thick with moss. But the park's most photographed landmark predates even World War I. In 1906, the four-masted sailing ship Peter Iredale ran aground on Clatsop Spit, and her rusting iron skeleton remains embedded in the sand within the park's boundaries -- a monument to the Columbia River Bar's fearsome reputation as the Graveyard of the Pacific.

From the air, the mouth of the Columbia is an enormous, shifting canvas of sandbars, breaking surf, and tidal current. Fort Stevens sits on the Oregon side of this chaos, a low headland that looks deceptively calm from altitude. The concrete outlines of old batteries are still visible through the tree canopy, and the Peter Iredale's ribs catch the light on the beach at low tide. It is a place where multiple centuries of American anxiety -- about the British, about the Japanese, about the sea itself -- left their marks in earthwork and concrete and rusting iron. The fort never fired a shot in anger. The one time an enemy attacked, the response was deliberate silence. That restraint may be the most memorable thing about it.