Early August saw my son in law David and two grandsons Josh and Gavin and me heading to the Sierras for some stream trout fishing. We use the classic Sierra stream rig: a limber fly rod with automatic fly reel and 4 lb. monofilament with nightcrawlers, or grasshoppers—when we can catch them. That set up allows us to reach all of a stream, with brush and trees at the water’s edge, without spooking the wild trout. The key is…