It appears that Colton will be serving the first part of his sentence in a maximum security Washington State prison.
Aside from the pun, I doubt Colt is really a "flight risk." He walked away from a no-security juvenile halfway house in 2008, but there's a huge difference between that and attempting to escape from an adult prison. I don't think Colt would even consider a breakout because when he ultimately got caught again he'd face losing an entire decade locked in a box.
Colt certainly has a sky-high offender score due to all of the felonies he pleaded guilty to, but with no shortage of murderers and rapists around, it seems like a non-violent offender would be taking up valuable space in max when there's no need for him to be in there. Colt deserves to be in prison, and he's going to serve a big chunk of time... but maximum security seems like overkill to me.
A reminder for those who've read or are reading my book, The Barefoot Bandit: The True Tale of Colton Harris-Moore, make sure to check out www.bobfriel.com for story updates, photo galleries, links, maps and a Google Earth tour of all the sites in the story.