This is urban fishing, for sure. Upfront I should say that this is not an easy place to fish for anyone who is not in decent condition. To fish Four Mile Run stream (history here) requires keeping one’s balance on a slope made of rocks and covered with metal fence-like material. It is slippery, and there is plenty of brush and such.
But the hassles are worth it. Four Mile Run stream offers lights-out fishing. There are tons of bluegills (easily taken on a size 6 snell, bobber, and worm) and large-mouth bass (I scored mine of a pumpkin green Senko worm Texas-rigged. Cast, let it drop for a few seconds, and slow reel in.) The bass range from pipsqueaks (6 inches) to hogs (7 pounds). Guys fishing drop-shot rigs with Senko and Zoom worms tend to do very well here. One inevitable challenge around this bridge is snags—they happen a lot.
Bluegill and bass are plentiful near and under the Jefferson Davis Highway bridge (south side of the stream).
To chase catfish, walk eastward all the way to where the creek meets the Potomac River (map here). I put out four lines today with fresh cut bluegill. I had two serious bites in two hours, and one produced a 10-pound channel catfish. It was a sizable one, but there are much bigger ones in there—forty to fifty pounders have been recorded by guys on FishBrain. The water level rises and falls, but fishing seems to be good here whatever the tide.
You can park in the Potomac Yards parking lot, which puts you a few minute walk from entry to the stream edge next to Jack Taylor Alexandria Toyota. Yes, you could get towed from the shopping center lot, in theory, but I have staved off this threat thus far by buying drinks and snacks from Shoppers and leaving the receipt and shoppers plastic bag on my dashboard.
Turns out the same day I was here, the Metropolitan Angler was landing small bass with a Rapala hard bait. You can see him do it in this video, and you can watch me pull in this catfish.