The person is first and foremost a trespasser. As such, you should first try contacting the police or sheriff, explain the situation to them, and ask them to remove this person from the park. You should also ask them to issue a no trespass order so that if the person returns, they can be arrested for trespassing.
However, sometimes law enforcement officers are reluctant to remove squatters even when they have the lawful authority to do so. In that case, you may need to resort to court action.
There is a “midnight move-in” statute (ORS 105.115 (1)(c)) that allows RV parks to immediately file an eviction case in court without notice if the owner or possessor of an RV places it on park property without the park’s prior consent. If you are forced to go to court, you would cite this statute on the eviction complaint when you file it with the court. At trial, you would present your case with testimony and perhaps a few photos to explain to the judge that the person is a squatter who should be immediately evicted.
There is another statute (ORS 105.115 (1)(b)) that also allows a landowner to file an immediate eviction case when a “person in possession . . . is holding possession without any written lease or agreement.” This would apply if someone doesn’t have an RV, but perhaps only a regular passenger vehicle and/or a tent. When you file the eviction case at your county courthouse, ask for and fill out the eviction complaint form for a tenancy not covered by ORS Chapter 90. In the section where you must indicate why the park is entitled to possession of the premises, check the “No Notice” box and write: “ORS 105.115 (1)(b) – Trespasser in possession.” The filing fee for this kind of case is more than a regular residential eviction case, but after filing the case will proceed like any other eviction case.
