There is a 60ft. easement along the length of the border owned by fedgov for the purpose of security. It is called the Roosevelt Reservation. https://en.wikipedia.org/wiki/Roosevelt_Reservation
Most of the land along the border in the Western states is owned by the federal government, something known as the Roosevelt Easement. This 60-foot buffer does not exist in Texas, where private landowners must give up their property for a fence to be built.
I’m just sure this is shown on their deed to the vacant land.