Neighbors Use Railroad As Free For All

Location: Oregon

We recently bought a new house out in the country that includes a railroad easement on the edge of the property. My understanding is that this means the land is ours (and we're taxed for it), but we can't do anything to block the railroad (it's decommissioned, but I assume we still have to keep it clear). Technically our property includes both sides of the railroad, but we don't really worry about the other side.

We've noticed a neighbor ride his ATV down the railroad a few times, which I don't like but my husband doesn't mind. Just now I saw a janky ass SUV driving down the railroad, and it nearly tipped over, which made me really nervous.

My husband says people probably think they're trespassing on an abdandoned railroad, not private property. Should we put up no trespassing signs? Or anything else? I recognize there's potential liability, too, if someone were to injure themselves.

EDIT: We know the railroad operator company, and no, it is not considered "abandoned." I said it was decommissioned (maybe that's not the right word -- not in operation?) because we know that the railroad only operates tourist trains now and they don't run through our neck of the woods anymore -- but I imagine they could if they wanted to. We've seen downed trees on the railroad and it takes a while for them to get cleared, too, but they do eventually.

I'm quite confident on the property lines, and the fact that the land is ours, but the railroad has the right to use and access the railroad itself. We're definitely not looking to block access to it.