SG-1's Cameron Micthell Question

Do we know when he became a colonel? In any of his flashbacks, is he a colonel? Thanks :)

SG-1 S6: Memento

Okay, so here's the next S6 ep I've watched.

( My Thoughts on Memento )

Now, all I have left is Prophecy! (And then stop avoiding Prodigy in S4...ugh, Hailey.)