Flow out of Island Park Dam was nearly doubled Wednesday. That action along with a big rainstorm the same evening has slowed fishing temporarily in the Box Canyon-Last Chance section of the river. The same could be the case for the river in the Riverside area where the big bugs will likely show very soon. This rise in flow is unlikely to impact fishing in the lower river where giant and golden stone fly adult patterns rule the roost with respect to being effective all the way from the slide below lower Mesa Falls to Chester. Here’s an update: as of Memorial Day the big stoneflies are beginning to fly in lower Box Canyon.