We were going camping  in the mountains. We had passed a lake and were on our way to the next campground. We came to a lake right next to a big army post, all surrounded by a high wire fence. This was the campground. The ranger told us we would have to carry our stuff in, as no cars were allowed, and we would have a specified campsite the first night. There was about 10 feet between the fence and the water. The lake was warm, and they had several lifeguards, and I thought we'd go swimming.