Three hundred yards upstream from where a spring branch enters the river, it widens into a pool with a large, slow eddy. Recent cold weather convinced me that smallmouth bass had likely migrated from the frigid river into the spring. If that were the case, their metabolisms would be quickened by the 54-degree spring water, prompting them to become active feeders. My 5-wt. rod delivered a slow-sinking intermediate line, a short length of 3X tippet, and a size 8 Ozark Woolly Bugger to the fast water seam. This enabled the fly to settle as it was swept outside the eddy. I repositioned twenty casts and one missed strike later so casts could be delivered to the slowest portion of the swirling pool. A line tug immediately answered a lift, drop, strip retrieve, and a strip-set of the hook revealed a strong fish. It immediately headed into the deepest portion of the pool with the most substantial current. That allowed a short but impressive run curtailed by palming the reel spool, and finally, the fish came to hand. I was surprised to discover that I had landed a Rock Bass. Ten more were captured from the big eddy before the action ceased as suddenly as it had begun.