Report 3270: Two experienced campers hear vocalizations unlike any thay are familiar with

It was dark and we noticed we were running low on fire wood. we walked down a trail on the south side of the campsite to get some wood from a small clearing we had noticed earlier. We were watching some lights move across Brown mountain trying to determine if they were the Brown Mountain lights (investigator's note:  apparently this is a locally known phenomenon), or just motorcycles.  At any rate it was about this time we heard the noise. We had our flash lights off cause we were watching the lights on Brown mountain, then we heard this long scream.  We stopped in our tracks and listened carefully.  The scream repeated.  It was coming from the south west of our location deep in the valley.  We hurried back up to camp and turned off the radio in the truck.  The scream continued.  Now this has been going on for a couple mins and the scream changed.  It would scream for a few seconds and then the sound would start to break up.  At the time we described it as a cackle like sound, but the newspaper article (that was found in the BFRO media files) described it as a yodeling sound, which is more accurate. This continued on for several mins, every few seconds another scream continuing on to the yodel.  Both of us are avid campers, and camp in this same area every October.  But we had never heard a sound like this before.  We first thought perhaps a mountain lion, because we had heard their cries compared to a woman in pain screaming.  We debated for a while and at last decided to move to another campsite for the night as we had not explored our surroundings much prior to nightfall.  We have yet to be back, but we have full intentions of going back and exploring the valley from which the sound came.