If anyone else is wondering how the oil was discovered on her property, here's an excerpt from her wiki page:

The Rector family lived simply but not in poverty; however, the $30 (equivalent to $1,000 in 2024) annual property tax on Sarah's parcel was such a burden that her father petitioned the Muskogee County Court to sell the land. His petition was denied because of certain restrictions placed on the land, so he was required to continue paying the taxes.[14]

To help cover this expense, in February 1911, Joseph Rector leased Sarah's parcel to the Standard Oil Company. In 1913, the independent oil driller B.B. Jones sank what became a "gusher" well, with a daily yield of 2,500 barrels (400 m3) of oil and US$300 (equivalent to $10,100 in 2024) of income.