recreation.gov is a .gov site. Which is supposed to mean it is owned by the government and not a private run site collecting fees for a for-profit defense contractor.
... because the USPS also pays their contractors.
The government hires contractors for most things, but the projects are still owned and directed by the government.
Specifically: https://home.dotgov.gov/registration/requirements/#eligibili...
See also RFC 920: https://datatracker.ietf.org/doc/html/rfc920 Section "Initial Set of Top Level Domains"