"The thoroughness of the closures this year makes sense only if you're banking on a long shutdown. Trash doesn't pile up overnight. And while on the first and second days of a shutdown it can seem idiotic to have cordoned off a playground at a federally run neighborhood park on Capitol Hill, by week three such a barrier will be a necessary legal warning that if you go in anyway and your toddler cuts herself on broken glass and that stayed there because no one is cleaning the place—well, that's on you, not the government.
"Without staff or funding to ensure the safety of visitors, the security of the memorials, and the continued operation and maintenance of park facilities, the memorials on the National Mall—just like Yellowstone and the Grand Canyon—are closed," Johnson, the NPS spokeswoman, said in a statement.
Cordoning spaces off or hanging signs in front of them even if they cannot be securely closed is a legal strategy for preemptively dealing with the things that can go wrong in abandoned spaces, and serves notice that if a site looks bad it's because of the shutdown, not willful neglect. D.C. has a terrible record of under-maintained public parks turning into disturbing hangouts for criminal activity, not to mention locales for trash-pileups and cozy vermin homes. In a shutdown of a couple of days, that's not much of a worry. But if could become more of one if the shutdown extends into November. (See my 2002 Washington City Paper piece, "Parks and Wrecks," if you want to a sense of what a public-safety disaster bad parks policy once created inside the District.) One week in, Mayor Vincent Gray announced the city would begin emptying trash cans in federally owned neighborhood parks that are easily accessible to city trash collectors, in a bid to prevent an increase in vermin citywide.
Already, there are signs of decay. C-SPAN's Howard Mortman tweeted on Wednesday morning: "#shutdown-related? Spotted 2 rotting roadkill deer carcasses southbound GW Pkwy this morning (below 123). GW Pky is a natl park @wtoptraffic." On his way home, he counted three carcasses."
Good article discussing the closures.
http://www.theatlantic.com/politics/archive/2013/10/how-the-national-parks-became-the-biggest-battleground-in-the-shutdown/280439/