I would guess there are a few still left in the lake, but I did see a guy hook in to a nice one on the creek below the lake a couple years ago. He had a baitcaster with heavy mono on it and did not stand a chance with all of the structure. The fiight lasted longer than I would have expected though. I got a pretty good look at it from my kayak before it broke off. I don't know of anything else it could have been. Some of the deeper holes in Paint creek(creek) now hold the Muskies from Rocky Fork lake. They are in there, but few and far between. I've had braided line shreaded on Paint Creek near Bainbridge a couple of times and it makes me wonder if thats what I hooked into on crankbaits.
I've lived within four miles of Rocky Fork for over 30 years and everyday I'm around guys that fish it often. In all that time I haven't heard of anyone catching a muskie. Last time I remember muskie being common on RFL was back in the 1960-70s.
I knew a guy that used to live in the South Beach Trailer park. He had permission to fish at the old mill below the dam and caught one around 27" if my memory is correct. He was fishing for bluegills when he hooked into it. This was back in the mid 80s. He ate it.
Last stocked in '97. Discontinued after several years of very poor return, in favor of Caesar Creek. The common complaint was that Rocky's fish kept going over the dam during high water. More than one veteran told me that the best fishing was downstream in the creek.
Fished the lake many times, including several tournaments, during the early 90's & never saw a fish off my boat. In one of the tournaments, there were actually 3 fish caught - the largest @ 39".
Given the lifespan of muskies in OH, there could still be a couple of large fish remaining, but it's definitely a very low percentage shot....