Newly discovered mineral rights

My sister and I just discovered that our parents deeded a small share of mineral rights to us on some property in Kay county in 1977. They did not own any other rights. Property is 15-27-3, southern half of SW4. Do we have any rights to royalties that my have occurred in the last 36 years? How do we find out about drilling activity that may have occurred? How do we keep up to date on current drilling if any?

Thanks, John