Basis of inherited Mineral Rights?

I live in OHIO and inherited 5.0761 acres of mineral rights in Eagle District, Harrison Cty WV on the passing of mom on 9/30/2004. All rights were sold in Fall 2016 at $1,750/net acre resulting in proceeds of $8,800. This was a non-producing well from which we'd been receiving small (under $5) royalties per quarter for several years. How can I determine the basis of the inherited rights so I can determine federal tax liability on my 2016 tax return? Is there any other tax liability I need to pay? Should the buyer be sending me some sort of tax form to use?