use the advanced search and owner, start with and the letter you are looking for. notice that both owner and placed by are used and challenges might accept only one. And of cource limit the search to location you are interested in
Another way is to add all local caches to a vgps and order or group by owner or placed by. It is only for paying members and will be problmatic with a area of more then 10000 caches.
And I would also say that a local GSAK is the best way to find caches like this...