Enable the housekeeping feature on the site you want by going to the Campgrounds tab, and clicking on the blue button underneath campsites. Click the pencil next to the site, and select the box for Housekeeping Enabled.
Once a site has been checked out, it will automatically be marked as 'housekeeping required'. You can view all of these sites requiring attention under the housekeeping tab, and mark them as completed as necessary.
