Report 6037: Hunter hears unusual vocalizations on two occassions

There were two separate incidents within 12hr time of sounds so unusual that, to this day, I can't explain or rationalize out of my mind.  I had arrived at a campsite near Thompson Pass, the evening before the start of deer hunting season. The campsite was about 500yds off the forest service road and in a dense pine forest, near a logging trail that led to a creek. I settled in for the night in a sleeping bag in the cab of my truck, waking up at about 0400, with the need to go to the bathroom. I rolled the window down and listened for any "critters", most notably bears. Grabbing a flashlight, I left the truck and relieved myself. As I was preparing to return to the truck, I began hearing the sounds of something breathing deeply to my left and to the rear. Shining my flashlight in that direction, I saw nothing, heard nothing move. I quickly got back in the truck, and then began hearing this warbling, like a man yodeling in a high pitch, from the direction of Thompson Mountain. I rolled up the window and stayed awake with my .44mag. I waited until dawn to leave the truck to hunt- I usually leave about a half hour before dawn, depending on how far I'll be walking to the area I plan to hunt, but those noises had really spooked me. I got to the heavily wooded ridge partially up Thompsom Mt, at  the convergance of two main game trails, remaining there until about 3pm, only seeing one small doe moving quickly head hunched down. I passed on it. I then began moving down back in the general direction of my truck, and keeping an eye on the area where a spring comes out of the side of the mountain, and trickles down to Witherspoon creek. From the area where I had been hunting came this bone vibrating sound, so loud with like multiple harmonics , its hard to explain. It was beyond a roar. I half expected to see a dinosaur crash through the trees, it was such an unreal sound. It lasted 4-5 seconds. I was out of there and on the way home, scared spitless. I've since mentioned the experience to a few co-workers, and none have had or heard of anything like it.