If you lost the house to foreclosure, toss it. No one is going to make a claim against you. If you have sold the property by deed, you have given a warranty to the buyer and their heirs and assigns. Oh, you'd probably be safe tossing it after 60 years. In the meantime, it doesn't take up much space, so I'd just keep it with your important records. Remember that your owner policy continues to defend you even after you have sold the property.