Hi, I would appreciate help with this question:

Back in 1994, my mother inherited a house from my grandmother (who had owned it since around 1930), and at such time my mother rented the house out. In 2011, my mother gifted the house to me, and I continued renting it out. In 2014, I sold the house for $75,000. Is my cost basis the value at the time my mother inherited it from my grandmother in 1994 (I'm assuming there was an Inventory with a value listed for the house from my grandmother's probate proceedings, though I live in a different state and so it may not be so easily obtained); or is the value what the county appraisal district had as a valuation in 1994; or is the value what my grandmother paid for it in 1930 (which I have no idea how to find out what that value is, but I'm sure it'd be very low)? This same scenario will apply to land when I sell it, but the selling price of the land will be much higher. Will the same response apply to it, as well? Thanks for your help!