The federal government shutdown is emerging as an ominous hurdle for marathon runners preparing for upcoming races that use national parks, including the New York City Marathon.
Several smaller races have already postponed or canceled events and New York City organizers are looking at contingency plans for its 48,000 runners on Nov. 3 since the race's early morning staging ground is Staten Island's Fort Wadsworth.
"Fort Wadsworth is a national park and is currently impacted by the government shutdown. NYRR is working closely with our city, state and federal partners to establish contingency plans in case they are ultimately needed," the New York Road Runners race organizers said in a statement emailed to CNBC.
When asked if that means NYRR has ruled out a cancellation, the spokesperson replied that "contingency plans are focused on conducting the race November 3."
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The 2012 NYC marathon was abruptly called off in the wake of Hurricane Sandy, angering many runners, and angering many residents that the event wasn't canceled sooner and its resources diverted to rescue efforts. The hurricane's ultimate economic impact to the region was calculated above $50 billion with more than 100 deaths.
By its own calculations, the 2011 race "generated a record $340 million for New York City, significantly impacting tourism, tax revenues, and the economy." The 2013 race will be the final year ING will be the lead sponsor of the New York race. Starting in 2014, the race will change its name to the TCS New York City Marathon to laud its new lead donor, Tata Consultancy Services.
The race, which sets foot in all five New York City boroughs, already takes in only a very limited area of Staten Island before runners cross the Verrazano-Narrows Bridge into Brooklyn.
Last week, Runner's World reported that several races were facing cancellations or delays, including the postponed Oct. 5 Run! Geek! Run! 8K event in West Potomac Park in Washington, D.C.
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The Woodrow Wilson Bridge Half Marathon in Virginia, originally set for Oct. 6, has been moved to Nov. 10. The Oct. 6 Jersey Shore Half Marathon was canceled since it was scheduled to take place in Sandy Hook national park in New Jersey. The Oct 13 Towpath Marathon remains in jeopardy since it would use a route through the Cuyahoga Valley National Park in Ohio.
The Freedom's Run Marathon in West Virginia and Maryland through four national parks—Harpers Ferry, the C&O Canal, Antietam National Battlefield and the Potomac Heritage National Scenic Trail—pledges to go on Oct. 12 "even if the government is still shut." On its website, organizers pledge to "use an alternate fun, scenic, and historic route starting and finishing in Shepherdstown if the National Parks are not open on October 12."
(Read more: Amidst DC gridlock, whispers of a grand bargain)
The Marine Corps Marathon is still on track for Oct. 27 on the National Mall, organizers told CNBC on Monday.
Other big city races are taking the the shutdown in stride. The Bank of American Chicago Marathon scheduled for Oct. 13 does not use federal land. "We are good to go for the race," Jeremy Borling, a spokesman for the race, told CNBC.
Follow Amy Landfield on Twitter @AmyLangfield.