My father died and left property in trust for my mother, my brother and I. (40 years ago.) My mother dies in 1989, and the property transferred to my brother and I. The trust was dissolved in 1994. I have paid taxes on this property continuously.

The property value has increased 10x. It will probably sell for between 1.5-3 Million dollars. Until 2004, the value was estimated (for property taxes) as $150,000. Property is coastal Georgia.

What kind of tax burden am I facing?

When you sell the property, you will have to pay capital gains.

The only significant question is what the basis for the property will be. I am not sure on this, so you need to contact a competent tax professional. If it can wait, make the contact in June. Everyone is busy right now.