400 is a wide swath of band
406-420 Federal
430-450 Amateur and very few Trunk
450-470 Plenty out there
470-512 Plenty out there
No one will have a Nationwide set of frequencies tho.
If the data was submitted, yes it will be searchable
Altho a little more info from you on what you are looking for will be helpful as well as updating your profile
to show a location, which might provide more QTH specific responses from members