A gate prevents visitors from entering Joshua Tree National Park, in Joshua Tree, California on October 2, 2013, the second day of the US government shutdown. National parks across the country are closed due to the shutdown, but what about all the people who aren't government workers but rely on government contracts to get paid?  - 

Government contractors account for more than half a trillion dollars a year in government spending, and like everything relating to the government shutdown, the question of whether a particular contractor is still on the job is: It depends. 

For instance, many contractors doing jobs where the money is pre-loaded can keep going. Unless, say, they need a furloughed employee to sign off on something. 

"I had one client who has a construction project going, and the actual site is now shuttered. It’s locked up," says attorney Elizabeth Ferrell, a partner in the government contracts practice at McKenna, Long and Aldridge.  

Big companies, like Boeing for example, may keep workers on payroll, but shift them to work on other projects. Smaller companies may not have that option, but they may be motivated to "suck it up longer," says Alan Chvotkin, executive vice president at the Professional Services Council, a trade group for government contractors.

"In the professional services world, the most valuable commodity you have is the people," Chvotkin says.  And replacing them doesn’t come cheap.

Follow Dan Weissmann at @danweissmann