Here's a picture of 4 footers on Mille Lacs in Minnesota. I was taking a picture of a loon but the wave covered him up. No pictures of western waters though. too busy trying not to die.

I have been in much worse waters on Mead. The worst was coming out of Vegas wash in a nasty storm. Not sure how big but while gowing over the crest of the waves at a 45 degree angle, the big motor was submerging and the bow was only a couple feet over the crest. Not sure how big like I said but John Murray and Byron laughed at me when I got to their house. John said it looks like 10 footers out there. I'd imagine he was close.

http://www.calfishing.com/dc/user_files/5711-wave.jpg

Attachment #1, (.jpg file)