Was Plame a "covert" agent?

Here is how to effectively debunk the bogus suggestion that Plame was not undercover when she was "outed":

Ask rhetorically: If Plame was not undercover, why then did the CIA ask the Justice Department to Investigate her "outing," and why did the Justice Department agree to investigate?

If she wasn't at least titurally "covert," how would the investigation have triggered a need for a special prosecutor? There must be some fire to the smoke.

Original thought was posted on a different blog. I'm paraphrasing.