On the trespass charges, most the land the protest took place on was on Standing Rock reservation, and used with permission, on federal land and used with explicit permission of the BLM, or on privately owned tracts of land and used with implicit permission in that the deeded landowner did not object to the use and their expressed objection would be necessary for it legally to be considered trespassing.

The destruction of property in this specific incident refers to a handful of people, including US Presidential Candidate Jill Stein, spray painting slogans on the scoop of a bulldozer. The main effect of this action was to protect the scoop against corrosion for a day or so before it was next used and the paint abraded again as it was once before on the first day the bulldozer was ever used after initially bought sporting a fresh coat of paint. Rather than bulldozer vandals from a scientific and practical viewpoint they would be more accurately described as bulldozer protectors.

There is also the issue that the specific land in question off the present "reservation" was acknowledged as being eternally the property of the Sioux people in a legitimate legal treaty ratified by the US Government, and the US Supreme Court has previously ruled that this treaty was legitimate and nothing abrogated it. So the issues of whether the US BLM correctly permitted the protest (they did) or the deeded landowner objected (he didn't) aren't even relevant at all from that legal viewpoint where all the land in question legally still belongs to the Sioux, not just from their own perspective, but from both ratified treaties and contemporary rulings of SCOTUS.