Saving Daddy's Land

My Daddy died five days ago, I let them let him go because he was always totally clear about his wishes. The issue is that he only agreed to give me control over his finances when it was too late. He died with a mortgage on his land that we live on of $15K. To lose it would not be horrid for me and my Husband. My Daddy's wish, however, was that this land be a legacy for my Son. He died with no Will. 
Please help.