The only real way to find out who to contact would be to hire a title company to do a title search and find out who the current owner is. Failing that you could run down to the county records office and do a search. If it is the previous owner, you will need to play detective and try and track them down through relatives or possibly send them mail at the address that will be forwarded. If it is a bank you will need to make contact with them. Don't bother with large national banks, when the house comes on the market you can make your move, but you won't get anywhere ahead of time. Smaller regional or local banks might be willing to talk to you. Good luck.
Coldwell Banker Burnet
licensed MN Real Estate Broker
Quite often we see properties where the former owner has moved out yet nothing seems to be happening. In some cases the property may still be in the redemption period (six months from the sheriff's sale in MN). If the lien holder (lender) does not apply for accelerated redemption the property may just sit there until the redemption period is complete. In other cases the lender may have control of the property but is not ready to list it. This process can sometimes take up to a year (or more) after the redemption period. A good Realtor should help you with answers on this property.