Report 24795: Campers hear lengthy call and response sequence between creatures in the Giant Sequoia National Monument

Loud whooping exchange was heard between at least two, possibly three entities at a range of no more than 500 meters. Deep whooping was projecting from the southwest, with answers coming from the south/southeast. The answer calls came in higher pitches and might have been coming from two different animals. The whoops could at times be described as moaning and other inflected noises I can't really describe with words. The exchange lasted for about 30 minutes. The higher ptiched calls shifted slightly from SE to E.