you could do a reverse search on that bank or phone number.
http://www.searchbug.com/companyfinder/

call that bank or email them about the check and account -
http://www.bankofoakfield.com/

but - if you give it to any gov agency make a copy of it and take down contact info of who you gave it to..
just in case they do something dumb with it -it will cover your fanny


http://www.usps.com/postalinspectors/fraud/fraudsch.htm
http://postalinspectors.uspis.gov/