That makes sense.
What you describe, you MAY have an action for "adverse possession
Adverse possession is a legal doctrine which allows an individual to acquire title to real property which belongs to another.
The statute governing the rules of adverse possession is Texas Civil Practices & Remedies Code Sec.16.021 et seq. ("CPRC"). The statute defines adverse possession as "an actual and visible appropriation of real property, commenced and continued under a claim of right that is inconsistent with and is hostile to the claim of another person."
Case law adds that it must be true that the possessor of the property actually does possess it (the belief of entitlement to possess is not enough), possesses it continuously (sporadic possession is not sufficient), and that he peaceably and intentionally asserts a claim of right to the exclusion of all others.
It is not enough to be merely caring for the property temporarily, or even paying the taxes on it, until the owner reappears.
SO in this case, if you took steps to "possess" the property. For example, built on it in some way, or regularly occupied or even traveled on the property? And have done so for 50 years? Then you have a great claim to adverse possession.
If that is the case, you can file a claim in the county court (the county where the land is located) and ask the court to transfer title to your name.
Now...if you do not meet the element of possession (can not show you have possessed the property) you have a few options. You can start to "possess" the property. Again, this can be as simple as building a fence or an outbuilding on the property and regularly visiting the property. If you do so? After as little as 3 years you can file a claim to modify title.
OR you can file a probate claim...it sounds like your mom may be a beneficiary
of your Uncle's estate, and you are a beneficiary of her estate...so you would have some claim to the property. The problem with this is that if there are other heirs to the property, they would also have a claim. Your mom and you would would have a claim for credit for the taxes paid...but it may be other heirs also have a stake in this. So if there is any way to file for adverse possession, I would go that route.
Let me know if you have more questions.