Determining a property line can be a bit tricky. The corners of the property line are often marked with rebar driven into the ground just below the surface. Nearly all real estate transactions require a plotted survey. County property records may have the coordinates of the property end-points. Many GPS units can then plot the property lines. If you have the plat with the house on it from
. the building department, you can measure the distance from the corners of the house to the corners of the property lines. Some counties publish these records free of charge online.