Strange noises in Pharaoh Lake Wilderness

Last weekend I was hiking in the Pharaoh Lake Wilderness with a buddy of mine.
We were headed back to the car around 9pm when we heard what sounded like 5-6 howler monkeys on the other side of a swamp close to the parking area. The noises went on for about 30 seconds before it went quiet. We then heard something large moving through the swamp grass out of sight from our flash lights. I have been racking my brain as to what it could have been and I thought that it was maybe bears fighting because I have experienced that before and the noise was a little similar. The strangest part of the whole thing was that there were clearly at least five individuals making these howling type noises. We also did not see any cars leaving the area so it’s very unlikely it was humans. We are both experienced hikers, hunters, and campers and have been recreating in the Adirondacks for years and have never heard anything like this before. I’m sure there is a logical explanation as to what we heard that night and was wondering if anyone has had a similar experience while in that area or in another area in the park.