While "mobile homes" are called mobile homes, they generally are not in fact mobile once they are set down on land: while they could be moved with effort (as almost any structure could be), they are typically affixed to the land (attached to it) and also attached to utilities (e.g. water, electricity, sewer or septic, etc.) serving the land. A mobile home attached or affixed to the land and not still on its wheels or on a trailer, waiting to be moved elswhere, would be considered an improvement; therefore, it would have been deeded to you.