I seem to remember it was a law passed quite a while ago that set aside one or two hundred yards along the border as Federalized.
I thought at the time it would be funny if the Governor of California objected to troops along the border, and then found out that one or two hundred yards didn’t belong to California or private property owners, but is Federal Land, and troops could be stationed there.
At that point by Executive Order the strip from California to Texas could be designated a military base and armed soldiers could be stationed to defend the border.
LoL that would raise some hackles with Moonbeam!
Are you referring to the Roosevelt Reservation. Government owns an easement along the border thanks to Teddy R
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(Even along the northern side of Rio Grande— Texas border )