So it looks like the typical setup across the country is:
1. Pay the annual USTA membership fee.
2. Pay the team roster fee to the organization running the local league.
For me in San Jose, the team roster fee goes to the "Norcal" organization and in your case it is "Foothills league of NC".
These local league organizations like "Norcal" and "Foothills league of NC"
are independently run organizations separate from the USTA and set their own team roster fees and other various fees.
Is that how it works?
Hmm...no, not exactly. USTA is the national organization. Everyone who wants to play USTA league tennis at any level has to first be a member of the USTA. The national USTA is broken up into 16 sections; some of these sections are a state, some are a collection of more than one state, and some are a portion of a state, depending on the general population and tennis population in those areas. (For example, Florida and Texas are each separate sections, while Northern California is a section and Southern California is also a section. I play in the Southern Section which is made up of 9 states.)
Each section is divided into districts with the bigger sections broken into more districts, etc. Then these districts are sub-divided into local area organizations/leagues. The Foothills league is my local league entity and it oversees and operates all USTA business and activity in a multiple county area of mid-NC. There are about 12-14 local leagues in NC. So Foothills is my local league which is part of the NC District, which in turn is part of the Southern Section of the USTA. It is still all under the auspices of the USTA, but at the grassroots level. While I'm not certain, my guess is that NorCal stands for Northern California (section) and that there are districts within that section and local leagues within those districts. It gets a little muddled because it isn't completely consistent everywhere with the dividing. Like in the case of Hawaii, because of geography, I believe Hawaii is a Section, but is not further divided into districts because it is not large in population. The order from top to bottom is USTA national organization, sections, districts, local leagues---but here and there, for special reasons, sometimes one of those layers is omitted.
Is that any clearer? Or did I just confuse you further? LOL.
If others know more than I do here, please feel free to jump in and correct me.