How Can I Find Out What Office Sponsered My Security Clearance Investigation?

I have completed the application for my security clearance but now I need to sign and send some documents to the office that sponsored the investigation. I can’t find the letter I was sent in the mail and that seems to be the only place the office name could be found. How do I find out which office sponsored me? This investigation is to update my US Army clearance.

How Can I Find Out What Office Sponsored My Security Clearance Investigation?

I have completed the application for my security clearance but now I need to sign and send some documents to the office that sponsored the investigation. I can’t find the letter I was sent in the mail and that seems to be the only place the office name could be found. How do I find out which office sponsored me? This investigation is to update my US Army clearance.