“How, precisely, did the feds end up with the title to that land? “
It was acquired from a treaty with Mexico, ending the Mexican War. Most of the west was acquired that way.
As a condition for allowing Nevada to become a state, Congress required the new state to “forever disclaim all right and title to the unappropriated public lands lying within said territory, and that the same shall be and remain at the sole and entire disposition of the United States.
The federal government did try to give the land away for many years, but in Nevada, water is more important than land.
So, fedgov received stolen property, and equally stolen water rights, from Mexico.
Seems to me they’re just mad about someone stealing the land and water rights they ‘bought fair and square!’ from the original thief.
“No officer! I bought that stereo FAIR AND SQUARE from that ‘fencing operation’ over there, It’s MINE I tell you!”