Multiple witnesses in Bonner County, Idaho

On October 7, 2017, my wife, myself and our dog went on a late season kayak paddle to Upper Priest Lake and overnight camping trip at Beaver Creek Campground. After loading the kayak after our paddle, we drove ½ mile to the campground, only to find that it was closed for the season. Not wanting to find another campsite, we drove around the campground to the Tule Bay boat launch parking area, which was still open. We parked our vehicle, unloaded our tent, sleeping and cooking gear and began to set up camp, carrying things into a designated site that would normally be accessed by the campground road. I was a bit concerned about camping in the site after the campground was officially closed, but figured that as it was already getting dark, it was unlikely that we would be confronted by a ranger. It had been raining and was getting cold, and my wife wanted a campfire to warm up from our paddle to Upper Priest Lake. I didn’t want to start a fire, as I was still uneasy about camping there and concerned that a fire would attract attention to us. After setting up the tent and getting things situated, we heard a whoo call to the north of us, across the road. I had the distinct impression that it wasn’t an owl, but a person whooing for someone in the dark woods, like someone trying to contact a hiker who was late getting back to the car (though there were no other cars in the area). The call was quite loud, louder than any owl I have ever heard. Too me, it seemed like it was coming from something (a person) with large lung capacity. By this time, it was dark and we couldn’t see anything beneath the tree canopy outside of our campsite. While my wife worked on starting a fire with wet branches (unsuccessfully), I arranged our sleeping gear in the tent. Suddenly, we heard a WHOO call that was much closer and much louder. This call made us nervous as we both felt it was made by a person who was creeping around our campsite in the dark messing with us. But we had heard no vehicles drive in, saw no headlights or flashlights, and it was too dark and overcast for a person to drive or walk around the woods without a light. My wife has better hearing than I do, and heard what she felt was an answering whoo from some distance away in the forest. Grabbing a flashlight, I walked 75 feet or so back to our vehicle to get my 9mm pistol. There was no question that this wasn’t an owl. The call was much too loud and gave both of us a fearful feeling. I could feel the loudness of the call in my chest. We noticed that our dog had no reaction to the calls, remaining in camp and not acting scared, but I sure felt that way, even with a firearm on my hip. After the last loud call, we didn’t hear anything more the rest of the night. No vehicles drove into the boat launch parking area and we heard no people or animals about. In the morning, I looked around our campsite but couldn’t see that anything had been disturbed. Later back at home, my wife researched owl calls online, but couldn’t find anything that sounded like what we heard. Whatever had made those calls around our campsite that night knew we were there and had a lung capacity much larger than an adult human male.