Am I legally entitled to my parent's land?

I think the answer to this would depend on a couple of things. First, was the property given to one party or the other in the divorce? Second, did either of your parents have a will that passed title? Third, Were either of their estates probated? Fourth, did either parent deed an interest in the land? You should take any documentation you have regarding the property to a real estate attorney in the area. You can find one using the Avvo "Find a Lawyer" tool. They may have to file an action to quiet title depending on what they find. If your father remarried, but owned the land prior to his second marriage, it should be his separate property, unless he deeded an interest to his second wife. Basically, the attorney is going to have to follow the chain of title to see who owns interest in it. It could that you own 100%, or just part, or nothing. It just depends on what the chain of title shows.

Whether your mother has an interest in the property depends on the terms of the divorce decree, which you will need to obtain a copy., and if she disposed of her interest by deed prior to death. If your mother had an interest in the property at her death, then it will pass under her Will if probated to person or persons named, and if she does not have a Will, then it will pass to her legal heirs, who have to be determined, which likely will be in an heirship proceeding. As to your father, whether he has an interest in the lands depends on the terms of the divorce and whether he has disposed of such interest by deed.

I'm assuming from your question that your "legal" father means that he formally adopted you and that this is not an informal adoption which may complicate matters. As the other attorneys already explained, you need to take all of the following to an attorney: 1) a copy of the divorce decree, 2) a copy of your mother's will and probate if any, and 3) copies of any conveyances/deeds that affect the property. It is only by examining all of these documents that anyone could determine current ownership. But to answer your question - no, you are not automatically legally entitled to your parent's land. Do you know how they held title - was it separate property of one of them or community property? If your mother still owned an interest at the time of her death, and she died intestate (without a will), you may be entitled to some interest in the land by statute. If she owned an interest at the time of her death and had a Will, then her interest would go to whoever she named in the Will. You are not legally entitled to anything owned by another person, and it is up to that person to determine how they want their estate distributed when they die. If your father has a legal interest in the land and he wants to leave his interest to his second wife and children, he may do so.