Determing possible lease

What is the path to learning if there is a current oil/gas leases on property?

There were gas/oil leases on Duchesne property until 1988 when my father-in-law believed he signed paperwork to allowed his brother to sell their interest in property. Father-in-law was never paid for sale and passed away believing he was owed $$ from sale. Now 22 years later, another owner has approached us asking for a quit claim signed in their favor. We explained the situation, other owner finally did title search (as we continued to assert that father-in-law believed he transferred property). Property search showed father-in-law owned land; husband as father's executor transferred property by warranty deed from father's estate to the both of us and we have paid our share of property taxes. Since there were oil/gas leases for decades previously (1960s-1988), how do learn about any current leases? Will a mineral search show leases? We do know there are no current well permits. Property is Twn 4 S, Range 2 west, Section 4.