We move ours to a private archive area where normal community members don't have rights so it doesn't show up in searches they do. FWIW.
As per the other replies @calebmt, as long as the users don't have access to the archived board, then the content will not show to users through search or navigation. Don't be concerned that you as an admin will still be able to see it. You can confirm the user experience by using the switch user functionality and double checking that they cannot view it.
Let us know if you need a hand with tweaking your permissions on the archive board.
Hi all, what if we don't want to put the content behind a permissioned wall? I'd like to have our archives public, but just not surface in search results.
Also, is it possible to restrict the lookback period in search to show results from the last 12 months only?