Report 58133: Early Morning Howls Awaken Campers Near Liliwaup

Awaken at 3:00-3:30 AM to the most cerebral frightening howl or roar I've ever witnessed. Sounded like the combination of a Howler Monkey and Bear's death moan. It sat us both up and my girlfriend who's a Wildlife Biologist and lived in the Yukon immediately asked me what was that.? I responded that I've never heard anything like it and initially said a howler monkey escaped from the zoo. It was long increasing howls that were felt as well as heard and had a tone and character almost primal in nature. They continued for 10 minutes at 2 to 3 minute intervals lasting 10 seconds I'm guessing. We both backcountry camped Glacier NP the Yukon and Denali and have never in our 30yrs of Wilderness exploration heard anything like this. I stayed awake until sunrise than slept until noon. Returning home we searched databases on North American mammals sound archives and found nothing like this. We found what we heard exactly under a Google search that played Sasquatch Vocalizations and decided we should at least report it. We don't know what it was and have no opinion as to it's source but can say with her Scientific Background and my Lifetime Wilderness Exploration we've never heard anything like this and now I wonder if perhaps there is something to Native American legends his grandmother told him about regarding "Stick Men" or "Forest Giants."