The pilot of a C182 made a precautionary landing for low oil pressure on a closed runway at a non-towered airport.

Narrative

While in cruise flight on a pleasure cross country with one passenger aboard the oil pressure gauge went to almost zero. We were over mountainous terrain and almost directly over an airstrip. I felt that it was necessary to land as soon as possible to prevent what could be a complete engine failure. I made two announcements on the CTAF that I would be landing on Runway XX at ZZZ. I circled over the airport twice while descending. There was a vehicle on the far end of the runway which would not pose a safely problem as I would only need the first one third of the strip to safely operate. Upon landing and taxing slowly down the runway I saw three objects in the center of the runway; which I gave a wide birth. I then noticed three individuals who had not been on the runway. One individual stated that the runway was closed and that I would have to depart immediately. I then back taxied to Runway XX and shut down the engine and checked the oil which appeared to be within limits and took off and flew back to our original departure airport. I had called for a preflight briefing approximately one hour before departure but was not made aware of any airport closures along the route; and was only planning on landing at our destination. If the individuals working on the runway had a hand held radio and were listing to the CTAF we could have communicated. If I had been flying alone I would not have felt the extra pressure for my passenger's safety and would have had the option to continue flying. I could have declared an emergency but I had no radio contact except declaring my intentions over the CTAF; which I did. The results of my actions caused no injuries or damage; which may not have been the case if; I had continued flying. Would I have done it again? yes. I could have requested the status of every possible airstrip within 50 miles of my flight path. Will I do that next flight? Definitely.