My go to solution for that was reddit.com/r/somecommunity which was local enough to have posts about lost cats and dogs.
More than once local media near me has literally just published a story that was first posted as text to Reddit.
More than once local media near me has literally just published a story that was first posted as text to Reddit.
I guess you just have to get everyone together in one place -- but that place could still be on the Internet.