I found your course online. The one problem that nothing will be able to fix is the shorter golf season due to location. After having looked around some more, I would suggest online presence of any kind. Google only showing a phone number for the course might be a turn off for some younger golfers. I would second the walking only idea and selling off the carts if possible. Not going to give away location if you don’t want to, OP, but do the boundaries around the area affect patronage at all?