In theory, fly-fishing is a simple sport: Pick a body of water, choose a fly-fishing rod, select your “fly” (or bait), tie a secure knot, cast your line and, hopefully, land a fish on the other end.

The last few times I traveled to the South Platte River at Deckers I left my favorite one-hand fly rod at home on purpose. It’s the perfect rod for the midge hatches that sometime occur on sunny ...