My maps show the land across the river as privately owned. Protesters had best go lightly. And that's the problem with large demonstrations. A subset of protestors decide to do something, they all get held accountable by law enforcement, who see them as a single unit. Saw it in the '60's, up way too close. You're not an individual, you're "them." You can never let your guard down, when one side is wielding weapons. It's not a location to be casually interviewing, certainly.
Irony is, the oil and gas folks continually rely on the General Mining Act (and subsequent modification acts) of 1872. The protestors are relying on the Treaty of 1851. Don't older claims generally win in court ... ?