Carla Beretta's suit names the Secretary of the Army and the man she accused of raping her, Eugene Jud Kneuvean, as defendants, Courthouse News Service reported.
Beretta said Kneuvean started making sexual advances to her in April 2007.
On the pretext of taking her out to lunch one day, he drove to a remote field in Riverside, Mo. where he raped her, the lawsuit said.
Beretta said Kneuvean told her he could use his influence to help her career in the Army but if she failed to cooperate with him he would hurt her.
The lawsuit details an incident where Kneuvean took her picture while she was performing oral sex on him and threatened to publish the photo unless she continued to engage in a sexual relationship with him.
Complaints to superiors failed to result in any action and Beretta was forced to continue to work with Kneuvean, the suit said.
She is seeking actual and punitive damages for assault and battery, a hostile work environment, emotional distress and gender discrimination.