A man calling himself "Dan Cooper" single handedly ushered in the era of modern airport security when he hijacked a plane on its way to Seattle from Portland. D.B. Cooper also spawned countless yarns, theories and debates as to whether he survived his jump from a Boeing 727 over southern Washington... in pitch darkness... in the middle of a rainstorm.
I do think that solving this mystery would be a shame. Living in concealment for 38 years, or moldering in a remote forest are both less interesting than a bona fide folk hero.