Isn't that the point of "dispersed camping"? It means camping outside of a designated campground.
Dispersed camping is the term used for camping anywhere in the National Forest OUTSIDE of a designated campground. Dispersed camping means no services; such as trash removal, and little or no facilities; such as tables and fire pits, are provided. Some popular dispersed camping areas may have toilets.
So yes, outside of a designated campground, but even with dispersed camping some places have designated camping areas. I think spread creek had numbered campsites.
Fishlake National Forest - Recreation