Fletcher's Cove straddles what must be the richest single niche on the whole 287-mile-long Potomac River. It's the upper tidal limit for ocean-going fish like perch, white and hickory shad, herring, and striped bass (known throughout the Chesapeake as rockfish), all of which stack up here in the spring to spawn. And it's the lower limit for coldwater species like smallmouths, walleyes, tiger muskies, and even the odd stocked trout washed down from one of the Potomac's feeder streams. There are also plenty of largemouth bass, crappies, bluegills, catfish, and carp in these waters. When the Park Service put in a handicapped ramp last year, they discovered a trove of Indian artifacts, leading archaeologists to believe the area had been a fish camp for centuries before anybody with iron hooks showed up.