A very nice explanation of the most likely cause and what people saw:
http://contrailscience.com/

All that said, as with so many so things, I lean toward the most probable explanation, but accept that a complete accounting is seldom available so we may never know for sure.

OK,Rocket Safety Inspector w/Masters in Aeronautical Engineering,State's the Contrary,To what I've seen!I've never seen a Contrail from an Aircraft,Leave a Residual Plume,As Long a Time,As this one did,& The reason why Aircraft Plumes don't last too long is the mixture of air intake with the Fuel!Rocket Engines Use solid Rocket fuel,& If Air is introduced,such as on an Intake port,The Rocket will Explode,hence my theory,of which wasn't explained,:Long Lasting Residual Plume!

A few problems with the aircraft contrail theory. For the effect as shown in the link

http://contrailscience.com/

the aeroplane has to be flying towards the observer. Now typically the aeroplane would have passed overhead and the mystery begin to unravel as it becomes more and more obvious that it a normal aircraft contrail. This would have occurred within less than 5 minutes as the aircraft passes overhead. This is why their is usually very little controversy is mistaking a missile launch contrail to a aircraft contrail.

This video and the description made by the observer indicates otherwise to a aeroplane moving towards the observer.

Also their appears to be the typical spiral effect in the contrail from a single propulsion engine. This would be typical of a SLBM with a single Solid Rocket Booster type engine. Combined with the light emitting from the contrail source (more than can be explained from sunlight reflection) then the answer is pretty obvious.

This is quite an easy one - its a ballistic missile launch.

The real mystery of course is why the US Government isn't admitting it. A Jack D Ripper moment possibly.

I still say Mitch Rapp was involved.