Location, location, location.
Campgrounds with utility hookups, over 50 sites, accept reservations will almost certainly have a camp host. (The USFS uses contractor companies to manage many campgrounds across the country. You won't know the host is a contractor employee unless you happen to see a corporate logo. They are the same type person as regular NPS and COE volunteer hosts and COE contract gate attendants. On the Details tab of the recreation.gov web site you might see something like "Managed by: " that is the name of the contractor company and strongly indicates there will be a host on site.)
Small dry camping campgrounds likely won't have a host.