Holland SP Beach unit is just off the beach itself but only 100-200 yards from the beach and as said on your northern limit.
However, just 20 miles farther north is Grand Haven SP and your RV site is right on the beach but you are not parked on sand as there's concrete and just behind your RV is actual beach/beach sand and/or the lake. A couple hundred feet away from most any campsite across the wide campground beach is the lake itself and the 1/4 mile long very wide public pier with 2 large lighthouses on it. Also the wide very popular "Connector Park" boardwalk going thru pristene park after park going to downtown right along the wide Grand River with restrooms, dozens of backed bench seats, food/ice cream/snacks/views/sgips/pleasure boats/playgrounds etc along the way while walking the .7 miles from your RV to a fantastic clean downtown and its so many attractions and all are free. You can ride your bikes or skateboards on the boardwalk also and leashed controlled dogs are welcome too.
Check it out on Google maps:
What you seek is really found from Holland SP and going north along Lake Michigan. 8 state parks I can think of quickly in just a 120 mile distance going north from Holland.