Meanwhile, sites like the Internal Revenue Service and National Weather Service may cease adding new informational or educational content, but will remain online for their core purpose. The IRS site will still be available for online tax filing, and the National Weather Service will continue to monitor and alert on weather conditions.

If you had imminent vacation plans, you might have problems. Planning a future trip will be impossible during a shutdown because the Websites used to reserve camp sites at national parks, to book tours, or to buy tickets to national monuments and sites of interest won't be available.

Any trips to Washington, D.C., will be fairly boring with no government buildings or museums open to visit. Even the National Zoo will be closed. Outside of Washington, national parks and other tourist attractions including Alcatraz prison, the Statue of Liberty, and Independence Hall will all be closed. You'll have to cancel hiking and camping excursions to national parks as well.

Shut-down Websites should direct visitors to a standard notice indicating that the Website is unavailable during this time period. If the Website is deemed essential and parts are still functional, the agency must include a message on the landing page informing visitors that information on the Website may not be up to date, and that any transactions or inquiries submitted may not be addressed until normal government activity resumes.

The United States government has far too many Websites to attempt to list all of the online resources that will be impacted by a shutdown. Suffice it to say, it is highly unlikely that a Website will be considered "essential" and allowed to remain online without funds appropriated to support it.