What felonies will they be charged with?

Violating the operating hours of a remote wilderness federal bird sanctuary?

They've done nothing felonious.

They are allowed to gather on public lands for redress of grievances (freedom of speech and to assemble peacefully).

They've broken nothing, destroyed nothing, threatened no one, and attacked no one.

The county sheriff asked them to leave, but the county sheriff has no jurisdiction on federal property, though their wish is to bring this land back under control of the county. Also, the federal government has remained completely silent thus far on this situation, and as far as I am aware they have not been asked to leave by federal authorities.

They are allowed to carry their firearms on federal BLM (the Second Amendment and upheld by the Supreme Court).

They live in their trailers and are camping.

They've broken into no buildings, hurt no one, taken nothing, and damaged nothing that I am aware of.

They are protesting and seeking redress of grievances, without; rioting, raping, stealing, looting, beating, shooting nor killing anyone... unlike many ethnic protests that have occurred in some cities recently... all of this in a remote wilderness location away from all homes, populations, and businesses.

Heck, even to be charged with trespassing, you need to be told to leave first by someone with jurisdiction, unless the area is legally posted with no trespassing signs, which it's not, nor have they been asked to leave by federal authorities that I am aware of.

So, what have they done that is felonious or even illegal so far?

They simply want their grievances heard and addressed.

Those are the facts as far as I can see them. Someone please correct me if I got anything wrong.