I grew up in Detroit, a city whose belching smokestacks and clamoring auto plants preach a relentless contempt for mass transportation. Yet when I moved to Washington, D.C., I fell in love with trains—the grand stations and comforting rhythms of the ride hooked me. I eventually ditched my car completely, relying solely on bike, cab and train for transportation.

Last fall, marathon training lowered my drinking and carousing capacity, opening gaps in my schedule that I devoted to scouring the D.C. area for fish. I rode my bike to Rock Creek, a small freestoner that burps and giggles through Georgetown, to cast for catfish and bluegills, and I rode out to the C&O Canal to chase smallmouth and shad. Though enjoyable, these trips merely fed a gnawing urge to fish for trout, and I knew it would be trains that would carry me to them. With timetable, guidebook, and map in hand, I began to plot out trips to trouty locales. A small Washington Post sidebar noted that Arlington County, which lies directly across the Potomac from Washington, stocked trout in a stretch called Four Mile Run. The lure of trout—even stockers—only a short subway ride from my downtown apartment, proved irresistible.

Four Mile Run flows through a sylvan, yet hardly wild, suburban park inhabited by urban mountain bikers and jogging, stroller-pushing yuppies. Though not as historic as other parts of Virginia, the Four Mile watershed does contain the remnants of three Union strongholds constructed to protect the capitol from Confederate marauders and a surveying obelisk marking property that once belonged to George Washington. Some also believe that Four Mile once supported a brook trout population, which prompts speculation that George himself might have once spent an afternoon chasing squaretails in Four Mile’s runs and riffles.

Heading out early one weekday amid a rush hour of bleary-eyed college students and harried commuters, I walked a couple of blocks to the Foggy Bottom Metro station. Emerging from the subway, I still had a 20-minute walk along a busy thoroughfare dotted with 7-11s, McDonalds and ethnic groceries before finding Four Mile Run meandering through the park. I’d seen the channelized version near Reagan National Airport, but this first glimpse of its pools, riffles, and waterfalls triggered my moving water fixation. I jointed my rod, rigged up, and after an hour of skeptical searching came upon four trout holding in a deep pool. I spooked them with my first cast but a sage senior nearby told me about a few of the savvier trout that took up residence in the more secluded pools upstream.

At the first likely looking spot—surrounded by steel girders and crumbling concrete—I saw a silver flash before losing my woolly bugger to a piece of overhanging rebar. A large oak lorded over the next pool though the stream appeared bent on ending its reign by undermining its root system. At its head, the stream babbled over big cobbles before flattening out. Undercut tree roots and a rock ledge formed two good lies and one side featured a sandbar ideal for casting. A manicured meadow and flower beds separated the stream from the bike path while the other bank hosted a picnic area, monkey bars, and a mom with the requisite baby jogger.

Descending to the sandbar, I saw a trout gently finning near the tree roots. Again, my first cast only sent the rainbow scurrying downstream. So, more out of frustration than strategy, I slung a long cast toward the end of the pool, began a strip retrieve, and the line tightened with the lively feel of a hooked fish. The leaping trout cracked the pool’s quiet surface and drew the attention of the picnickers who witnessed a stage-frightened beaching.

I decided to try again at the first pool and a twin of the first fish smashed my bugger and just like that I had a second nice trout. I retrieved my rod case from its hiding place under the bridge rafters and headed back to the Metro, enjoying the awkward side-glances of my fellow commuters, who seemed thoroughly dumbfounded by the sight of a trout fisherman on the subway.

—Scott Alexander Burrell remains car-less in the Capital. But he’s accepting donations.