I haven't traded my WM through RCI recently ... but presently, through the WM>RCI portal, see at least 8 HGVC properties with units ranging from Studio through 3BR. The locations include San Diego (Marbrisa), Orlando, LV, & Myrtle Beach.
Using my standard RCI account, I see these locations plus Breckinridge and Park City.
EDITED TO ADD: I just realized, the WM>RCI portal likely has the CO and UT locations, as well. I am not seeing them right now because these don't start with the word "Hilton" which is how I filtered the set located in the WM>RCI portal. The standard RCI account has an advantage over the portal in being able to find "all resorts of a given property family" ("HGVC") regardless of how they are named. So, don't discredit the WM>RCI portal! I bet it finds them all if I cared to dig, dig, dig.
Edit #2: Yes, the WM>RCI portal finds the Breckinridge property, "Valdoro Mountain Lodge (#6388)." Tricky. The word "Hilton" isn't anywhere in the name!
It also finds "Sunrise Lodge, a Hilton Grand Vacation Club (#D412)" (Park City).