During the Bundy Ranch stand off, there was also an article about the BLM intending to claim a large area of land along the southern border - Texas area IIRC. Lot of research regarding who owns what. Numerous law suites and went to Supreme Court. Seems like there was also an Indian Tribe involved with part of it.
That’s all I can remember though.
Are you thinking about the red river? Border issue between TX and OK. Not sure but I think the BLM wanted to claim a wide swatch for the feds.