Having fished the Delta Clearwater River 4 times in the past 5 years, there are definitely grayling over 23" in it. The Clearwater is a crystal clear spring river that has a very good insect population which makes for a good amount of fatties. This particular section is C&R but you can keep one grayling under 11". I don't understand the theory behind that because I've never caught one under 13". Below are some pics from my 2011 visit when we took a boat 3-4 miles upriver where there are a lot more grayling in the 20" mark. If a new state record grayling would come out of AK, it wouldn't surprise me if it came from the Clearwater; although I speculate the one in the video is 26". Looking at the size of its head, I'd say it's at least 20". If anybody wants to catch 50+ grayling a day on dry flies, take a trip to Delta Junction.