Report 15344: Possible vocalizations heard near Lake Tahoe

Last weekend my girfriend and I went to join her family at Sugar Pine Point in El Dorado County next to Lake Tahoe for a camping trip. On the early morning hours of Saturday July 22nd I was awakened by a strange whoop/howl. I immediately woke my girlfriend up and asked her to listen with me. We were sleeping in a tent. The howl we heard was not close to us. It was at a distance but was very loud. My girlfriends' aunt and uncle were sleeping inside a camper trailer about 50 feet away from us and they said they heard it pretty clear. They have been camping there for years and we all agreed that it was something none of us have ever heard. The whoop/howl lasted 3-4 minutes with short intervals of rest. At one point during the whoop/howl, it almost sounded like there was two "animals/things" making this strange noise.