My two sisters, my brother and I inherited the 120 acre farm when our Father died without a will. The probate judge give us undivided interest to 40 acres without restriction, and also undivided interest to 80 acres which our Mother had the use of for as long as she lived. Four years ago, she also died.

I suppose that we pay capital gains taxes back to what it was worth 60 years ago, for the portion of the farm which we have not already sold... 95 acres.

Any advice ?

The basis (fair market value) of the farm is its value at your father's date of death. You compute your gain or loss from that date.