The military escort aircraft—an F-106 Delta Dart and a T-33 trainer jet—were shadowing the 727 from what the FBI described as a safe distance. Neither aircraft observed anyone leaving the plane. This is not surprising given the darkness, the aircraft’s position relative to the escort, and the conditions.
Where exactly the jump occurred has never been definitively established. The aircraft was on a southward heading, and the crew’s instruments and recollections allowed investigators to estimate the aircraft’s position at the time of the tail pitch. The initial estimate placed the jump zone in the general vicinity of Lake Merwin and the town of Ariel in Cowlitz County, Washington. Later analysis using wind data, altitude, and aircraft speed pushed some estimates further south and east, toward the Washougal River watershed in Clark County.
The difference between these zones is significant. The landscape of Clark County east of Vancouver and the Cowlitz County terrain north of it are both rugged, heavily forested, and laced with rivers and streams. A person landing in either area in the dark with no navigation equipment, in a business suit, in winter conditions, would face serious challenges simply reaching a road.
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## The 1971 Search and Why It Produced Nothing
In the days immediately following the hijacking, the FBI and Washington State law enforcement launched what was described as a significant ground search in the areas where Cooper was believed to have landed.
Army and National Guard personnel combed through portions of Clark and Cowlitz counties. Volunteers joined the search. The FBI requested a specialized aerial survey, and an SR-71 Blackbird reconnaissance aircraft—a high-altitude spy plane normally used for national security surveillance—made photographic passes over the presumed drop zone. Divers searched portions of Lake Merwin. The search continued for some days before being scaled back.