"Without a resolution to the government shutdown this week, the Marine Corps Marathon as planned is in jeopardy of being canceled," MCM said on its Facebook page.
"While still considering and exploring all possible options, the MCM has targeted this Saturday, October 19 as the date to officially notify runners of the status of the event."
More than 60 percent of the marathon's course is on National Park Service land, Marathon spokeswoman Tami Faram told Runner's World Newswire.
The Army 10 Miler, with some 35,000-people expected to run on Sunday, Oct. 20, may be re-routed to avoid federal land, the race's Facebook page reported. A decision is expected Thursday.
The shutdown has already forced the postponement of the Wilson Bridge Half Marathon from Oct. 6 to Nov. 10.
MCM weekend generated $31.7 million in spending for the Washington DC Metro area in October 2006, according to a report from the George Washington University International Institute of Tourism Studies.
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