Most courses (public) have an entire grounds crew, or at least a local club to help maintenance.
Sadly...this is a subject that could be discussed at length.
Public courses may occasionally have a grounds crew but I would say it's not common. At least in my area. Typically if at a public park, the city employees only maintain the park itself. The course is left to the club.
Sad part is, a lot of clubs only have a core group that actually does most work. Others are more often than not only interested in playing. Typically they're the same people that complain. To get a larger group together, occasionally a scheduled work day will get some more to show. But even then, sometimes you have to give incentive (free entry to a club event, lunch, whatever) to even get a decent group for a work day.
When you actually get out there and spend time on a course, put in voluntary labor, and see what it looks like before and after, you gain a bit more appreciation and understanding of what it takes and what goes into maintaining a course. Sadly (again), many people don't even consider that part of it. And it's a lot more involved than one would imagine, especially this time of year.
It would be great if more folks were geared toward helping but I don't see it too often. Even bringing a tool to clear undergrowth during a round, clearing limbs, etc. Every little bit counts.
Maybe things are different elsewhere and there is great involvement from club members as far as maintenance goes within some clubs. But here, it's more just playing disc golf.
Much respect to folks who put in the time to make their courses better. Sounds like a full time job up at Highbridge Hills. It truly does improve the enjoyment for others, even if it goes unnoticed or people aren't aware of what the course may look like without the work.
/letters./rant.
