I recently went through the process of requesting that the FAA add a hang glider activity area label to Chelan Butte, which has been a world-renowned hang gliding and paragliding site for decades, and I would like to document the process publicly since it took some time to get on the right path. The process is the same for Long Term Aerobatic Practice Areas (LT APA), Gliders, Hang Gliders, Ultralight, and Parachute Jumping Areas. The FAA has no symbol specific to paragliders, but as far as other aviators are concerned, they are probably similar enough to hang gliders that it doesn't matter much.
To properly submit this request, you need to contact your local FSDO. They will put you in touch with an Aviation Safety Inspector (ASI) who will be responsible for filling out form 7900-11 and submitting it to the Aeronautical Information Services (AIS) on your behalf. You will need to provide documentation that your area meets the minimum level of activity. For Hang Glider areas, this is 400 annual flights.
I submitted a link to competition results which documented 900+ flights in a two week period, plus a link to https://xcontest.org/ showing 664 flights in 2021. You may need to work with your ASI to find out what kind of documentation will be accepted in your case, since the guidelines do not appear to be very concrete.
More details about the procedure are available in this document. It took me quite a bit of effort to find this. I initially tried to go through the process documented on the AOPA blog, and available on sectional charts. I emailed the FAA address listed there, which started the process. Eventually I was told that I needed to fill out Form 7900-11. Unfortunately, that form is only available to US government employees, so this appeared to be a dead end. I called the phone number and left a message with the AIS, and shortly thereafter got a call back. The person on the phone wasn't responsible for handling specific requests, but was happy to help once I explained the situation. She re-submitted my request with the additional explanation that Form 7900-11 was only available to US government employees, and told me to call back if I didn't get a better response this time.
Fortunately, the same person who initially closed my request promptly responded, apologized for giving me incorrect information, and sent me the N 8900.559 document, linked above. This document says it was cancelled on 8/28/2021, but I was told about it on 3/2/2022 and there does not appear to be a more current document describing this procedure. I would assume that this document will remain current until a new procedure is published. Armed with this information, I called the Spokane FSDO and explained what I needed. The ASI who called me back wasn't familiar with the process, but was happy to help. I sent him the N 8900.559 document along with basic information about the flying site and documentation of flight volume on 3/11/2022, and he informed me on 3/16/2022 that he had submitted the request and it would be on the 5/19/2022 chart.
The new charts were just published, and I confirmed that Chelan Butte is now marked! It's worth noting that this does not give hang glider and paraglider pilots any special privileges or priority. It's just there to alert other pilots to use extra caution because there may be a large number of hang gliders and paragliders in the vicinity. We are still responsible for following FAR Part 103, but hopefully this will increase awareness and help avoid potential conflicts between different aircraft types.