Screaming or howling in Scott County, Iowa

My girlfriend and i were camping on the Wapsipinicon river near Hwy 61,we were having a great time and decided to turn in,after about 15 minutes,out of nowhere came an incredible primal scream,the loudest thing i've ever heard,i was raised in the remote woods of the State of Maine,i've heard everything there is to hear in the woods,wolves killing deer,bears that were shot,rabid animals ect ect,iv'e heard cattle being slaughtered,wounded moose,honestly pretty much everything.As i kid i often went camping by myself for several days in the wilderness,i was too young to be scared and all i ever had was a single shot .22 rifle,i am not a stanger to the wilds,this is what im trying to stress,i was a little Jeramiah Johnson,lol,or so i thought.This scream was like nothing i've ever heard,but in Iowa?I do not tell any about this,only my ex knows the reality of the situation{we are still friends and she will verify}.It was so close to us i could judge the height that the animal was,between 7-9 feet of the ground,it was so loud it literally went "right through us"I was so frightened that i would not leave the tent.Im not writing this because i want attention, on the contrary.About 6 months after this happened my girlfriend and i were watching a show on bigfoot,the primal scream that was played{from a recording in Oregon} on the show literally made the hairs stand up on our necks,imagine that scream at less than 20 yards from you in the middle of the night and you can try to begin the magnitude of this event.I now feel very fortunate to have been this close and had such an encounter,i have been back in this area many times but never seen tracks or heard anything,but i walk a little slower and a whole lot more alert.I am a experienced Turkey,Deer,Bear and small game hunter{i dont hunt anymore} i just want to stress my expertese in the woods,what we heard was as real as it gets.