I have fished the damsel hatch at Chopaka on three different occasions since Cabezon's trip there at the end of June, and his report gives some good insights into what to expect when these bugs are present. As Irafly said, these Chopaka fish really get keyed in to the adult damsels, even to the point where they are ignoring everything else (including the damsel nymphs- confirmed my numberous throat samples I took over that three day span). If you are fishing in areas of the lake where the fish are active at the surface on hovering damsels, unless you are fishing a pattern that can suspend a few inches above the surface, you are out of luck. However, as Cabezon indicated, there are fish which are simply "sipping" if you will, and barely disturb the surface as opposed to those crazily jumping out of the water, which in general represent the majority of Chopaka fish during this hatch. With some patience, and by targeting those fish sipping at or just beneath the surface, you can have some great success, although it may be necessary to adjust one's own expectations given all the surface activity going on around you. The first time I hit this hatch at the end of June, first of July, 95% of the fish were keyed on the hovering adults and I was out of luck, though I did pick up two fish on callibeatis nymphs fished dry (with desicant powder to keep them on the surface), but that clearly was not the answer. I had no damsel adults with me that day, and I only fished the first two hours of the hatch which really got going that day about 12:30-1pm. When I left the water, they were still jumping everywhere. That first trip out though was a frustrating, but helpful learning experience. I came back a less than a week later on the 5th, and was able to fish the hatch from beginning to end. Similiar to the last time out, the bugs were thick by noon and fish were surfacing (coming out of the water) everywhere. Ignoring what my eyes and ears told me, for the two hours preceding the hatch (10am-noon) fish could be caught subsurface though they were already starting to look for the damsels above the surface. Did well fishing a blood worm in areas where fish were jumping and rising. That being said, this subsurface bite died off completely for me and it seemed if you wanted to catch fish, you had to match the hatch and that meant presenting damsel adults. Fortunately this time out I came prepared and had some different patterns with me to try. This was important, but not the only piece to figuring out the puzzle. Two patterns worked really well that day- both a standard blue that was a pretty exact size and color imitation to the naturals, and a "mating damsels" pattern. I surmised this was the case because in the midst of all the hovering damsels, especially as the hatch progressed into the later afternoon hours (2-4pm), if you looked carefully you could see both mating adults and single blue adult damsels floating flush in the surface film, along with tenerals. At first, there were not many fish looking for these, but those that were could be identified by the subtle, almost inperceptible surface disruption that would occur when taking adults in the film. These fish could be caught and would willingly, with total confidence, take the artificial if the timing of your presentation was right. In watching a guy (and later speaking to him) who was taking fish on the surface when most were struggling, it was important to "wait" and present a fly only to those that were keying on adults in the film, which were in the minority compared to those looking for the adults hovering above the surface. It meant very little casting, keeping your head on a swivel while constantly scanning an area for these fish to present themselves. The easiest ones to catch were those that were feeding in the film multiple times in rapid succession as opposed to a fish that would come up simply once and then would disappear. Once they were identified, the process itself was pretty simple- make a cast within the feeding window where the rise occured and wait. Sometimes the take would be immediate, while other times it took a while for the fish to find your bug, but once it did, the take came and it was game on. Every cast had a purpose and was directed to a specific fish- simply blindcasting to different areas and waiting for a strike only would produce frustration, as would casting to fish that either exploded at the surface or came clear out of the water in pursuit of damsels. Fishing in the aforementioned way, brought slow, but steady success which gradually increased (in terms of numbers) as more and more adults, tenerals, and mating adults were floating in the film that began attracting the interest of more and more fish, which gave us more opportunities to get bit. From 3-5pm (roughly) it went from 3-4 fish an hour to 6-8, which could seem like not a lot given the prepoderance of surface activity going on all around you, but was given the conditions and opportunities available. There was a period of time during the hatch when the mating adults was the only one they would take (I was fishing a mating adult and standard blue adult in tandem). In about an hour-hour and a half there was a 6-8 fish run on the mating adult, only to completely reverse itself in the last hour or so on the water that day. Simply food for thought. Fished it for the last time yesterday and the damsels were there, but there were not nearly the same numbers of fish concentrated and looking for them as there was a week or two or three earlier. You really had to work to locate the fish feeding in the film and put yourself in a position to cast for them, as there were few and far between except for a brief hour or two from 11:30-1pm. There was more random and isolated feeding in the film where maybe a fish would come up one time and that would be the only rise you saw in that area for quite a while. Patience, obeservance, and persistence were the key to a 3-4 fish an hour day in 6-7 hours on the water. A great hatch to fish that can be really frustrating at times, yet can offer some great opportunities to catch fish on dries, which is something most of us enjoy a lot.