Screaming or howling in Fresno County, California

My story of Bigfoot was not visual but rather we heard a scream in the deep forest that we could not explain. The location was in the area of Mono Hot Springs, in the Sierra Nevada's in California, specifically, the John Muir Wilderness. My brother friend and I were fishing at Doris Lake near dusk. Doris Lake is roughly a mile and a half hike from the resort of Mono. Nothing unusual was happening and then out of nowhere, we heard a scream come from across the lake and up in the Mountians. There were no people or animals that we could see anywhere. We were in the proverbial wilderness. My brother and I looked at each other, and unable to readily discern what we were hearing we continued to fish. I did say to him, if I hear that again I am out of here. Well, a minute or so later, the same scream. The three of us immediately reeled in and began to run all the way back to the resort, without stopping. I have listened to various recordings of alleged Bigfoot, and I am struck by how similar these recordings are to the scream that we heard. I did not see anything, so I cant be sure, but I am fairly certian what I heard was not a human, bear or mountian lion. So....what could it be? Note: my brother and sister worked for several years at Mono Hot Springs. My sisters good friend who worked their as well had a horse which she kept in the summer time at the springs. While riding in the back country, she claims to have seen Bigfoot walking through a meadow below a bluff she was riding atop.