This is another series that took a lot of time and observation to develop. Maybe the most significant observation and correction was that the vast majority of adult stonefly patterns have broad, bulky or heavily hackled heads, wherein reality stoneflies have very slender head profiles. These are very complicated flies to tie but when done right, they perform exceedingly well and are worth the effort (or should I say the effort of the expert factory tiers, who are far better at tying them than I ever was!).
These patterns have highly accurate profiles, great specific density, realistic jointed rubber legs and are darker and more realistically colored than most commercial patterns. Also note the slim head profile on the Salmonfly and the bulkier head profile of the Golden, both of which are key. They also have realistic segmented bodies and high-vis locator patches. Just put it where it needs to be and maybe wiggle it once or twice.