The St Olive Sow was my very own creation--based on the sow bugs I've pumped from the stomachs of trout on the Caney Fork River. But--It is basically a variant of the CDC France Fly. The fly seems to work best during shallow water on bright days. Fundamentally... if this fly isn't working, then the Jack Daniels is... and if the Jack Daniels isn't working, then the St. Olive Sow is. If you're able to get the fly down onto the bottom without drag of any kind (subsurface and surface), then you'll be catching fish. 1 note of special interest... the St Olive Sow has out-performed the Jack Daniels on nearby spring creeks.