http://www.uniformlaws.org/ActSummary.aspx?title=Residential%20Mortgage%20Satisfaction%20Act
When a mortgage is to be paid off, the mortgage holder generally owes the landowner two things: 1) a payoff statement showing the exact amount of funds required to pay off the loan on a given payoff date, and 2) a publicly recorded document in the local land records clearing the title of the mortgage lien once it is paid.
The "local land records" usually is the county court.