Write down the wrong date and you'll get caught out. The 51st Marine Corps Marathon runs Sunday, October 25, 2026, starting at the Pentagon North parking lot on Route 110 and finishing uphill at the Marine Corps War Memorial in Rosslyn. But if you live anywhere near the closure grid, the disruption doesn't wait for Sunday morning. It starts Saturday afternoon, and it reaches streets no runner will ever set foot on.

That's the part the race-day previews skip. The marathon course covers 26.2 miles. The closure footprint is bigger than that, because Arlington also shuts down the feeder roads that funnel traffic around the course, whether or not those roads carry a single runner.

The Course Is 26.2 Miles. The Closure Map Isn't.

The route itself is well known by now: start near the Pentagon, cross into Rosslyn, run through Georgetown and the National Mall, then come back over the river for that uphill finish at the War Memorial. What gets less attention is the second layer of closures Arlington County has posted in each of the last several years, on streets that sit outside the course entirely.

In its report on the 2025 50th-running closure list, DC News Now reported that the county shut down the eastbound lanes of Langston Boulevard, the westbound lanes of Spout Run Parkway, N. Lorcom Lane, and N. Rhodes Street from roughly 6 a.m. to 11 a.m. None of those carry the race. They exist to keep cars from spilling onto the actual course, which means a Cherrydale or Lyon Village resident with zero interest in the marathon still can't drive into Courthouse or Rosslyn during that window using their normal route.

What Actually Closes, and When

Arlington hadn't posted its official 2026 closure map as of this writing. The county typically releases it three to four weeks before race day, so expect it sometime in early to mid-October. In the meantime, the pattern below, drawn from last year's 50th-running closures, has held steady for at least three years running and is the best planning tool available right now.

Double check the final version at Arlington County's traffic alert page or marinemarathon.com once the 2026 map goes up, but plan your weekend around this shape now rather than waiting.

The Saturday Trap

The stretch that catches people off guard isn't Sunday at all. As WJLA reported, southbound Route 110 between Washington Boulevard and Route 1 closed at 4 p.m. on Saturday last year and didn't reopen until 5 p.m. Sunday, a 25-hour window that starts a full day before most residents think the race has anything to do with their weekend. If your Saturday plans put you south of the Pentagon after mid-afternoon on October 24, that's the closure to write down first, not the ones that start Sunday at 3 a.m.

If Your Sunday Already Has Plans

Arlington's Sunday farmers market, the Columbia Pike Farmers Market at Pike Park, runs 9 a.m. to 1 p.m. and sits outside the core closure list above. But anyone driving down from north Arlington will hit the closure perimeter on the way there, so build in extra time rather than assuming a normal Sunday-morning drive. The Westover Farmers Market, also Sundays from 8 a.m. to noon, sits closer to the affected corridor and is worth the same caution.

The Saturday markets, FRESHFARM's Courthouse market and the Cherrydale market, both wrap by noon, well ahead of the worst closures. But if your Saturday market run turns into a Saturday afternoon errand run south of the Pentagon, you'll run straight into that 4 p.m. Route 110 closure. Arlington County keeps the full list of market locations and hours on its farmers markets page if you're mapping a Sunday around one.

Metro Is the Move, With One Exception

Last year, WMATA opened early on race morning, with trains running to Pentagon and Pentagon City stations before 5 a.m. Pentagon station sits about half a mile from the start corrals, Pentagon City about eight-tenths of a mile. For the finish, Rosslyn station is the closest stop to the War Memorial at roughly four-tenths of a mile.

The exception is Arlington Cemetery station, which stayed closed until 9 a.m. last year. If that's your regular stop on a Sunday, plan around the later reopening rather than showing up expecting normal service.

Rideshare doesn't disappear either, it just relocates. Morning pickup and drop-off moved to the 1100 to 1200 block of South Hayes Street, while afternoon and Finish Festival traffic funneled to the 1900 block of North Lynn Street. Curbside pickup anywhere near the actual course won't work that day.

Don't Plan to Watch From the Bridge

If you're hoping to catch a runner cross the finish, know that organizers tightened spectator access last year beyond what earlier races allowed. Spectators weren't permitted on the Arlington Memorial Bridge or Memorial Avenue, and there was no route to the War Memorial finish line or Finish Festival that didn't cross one of the closed streets listed above. Anyone planning to watch should build their viewing spot around the closure map, not just the race map.

Why This Year Feels Quieter, and Why That's Misleading

Last year was the 50th running, and it drew a record field, pushing past 40,000 registrants and making the race, by organizers' own count, the third-largest marathon in North America, ahead of Boston in size for the first time. This year is the 51st running. No round-number anniversary, no record-field headlines, which means it may not dominate group chats and yard signs the way last year did.

The same core streets, Fort Myer Drive, Wilson Boulevard, the Route 110 segments, the Langston Boulevard and Spout Run feeder closures, have repeated across at least three straight years of race maps. A lower-key October doesn't mean a lower-key Sunday morning on your street.

Arlington's calendar has more of these choke points than the average preview article bothers to map out, and knowing exactly which block goes quiet and which one turns into a detour is the kind of local read Jesse Oakley builds into every conversation about this county, marathon season or not. If you've got a question about how race weekend, or any other Arlington fixture, actually plays out on your specific block, book a consultation and get the block-by-block version.