Stonefly Nymph Box (SwittersB)

Ah, May/June! Chasing the Salmon Fly and Golden Stone crawl outs and hatches. Fishing your nymphs on the bottom where they crawl toward shore or below the rapids, where they have been dislodged and been carried into slightly deeper water. It is a fun Western U.S. event and interesting to witness the actual emergence (crawling onto shore/emergence from the nymphal body).  

This action will carry on into July depending upon water temps. The California Stones (Salmon Fly) will end first and the Golden Stones will linger longer. It is a chuck it-sling it-stay tight to the fly-short line-drift affair. You can and probably should attach a second fly to the Stonefly (smaller nymph or a wet fly). Just remember, to avoid tangles, to think of your cast as a lob, open loop affair rather than trying to produce a standard cast with a tighter loop. Tangles and hooks into the back of the neck may result. Some will advocate throwing a longer line, and indeed sometimes you will have to chuck and duck and mend to get to a prime lie. But, I would advise the beginner to fish shorter and tighter to the fly with only  a mend or two at most.  Casting a heavy nymph by loading rod with water tension…

http://tongarirorivermotel.co.nz/2010/08/casting-tongariro-bombs/