Update: The "mysterious" plane over Denver was indeed an E-6B Mercury, TACAMO - a mobile command platform used by the US Navy - the extra bumps are for communication equipment. While it's unknown exactly what it was doing, it's not at all mysterious. They fly practice and testing missions all the time. The only reason people noticed this one was that it left a nice contrail that showed the curved path it was taking.
48.5 KB Views: 361
6.2 MB Views: 484