Depends on the type of title the park has on the land, they may very well own that part of the creek, or the land the van park is on may be the only access point. I wouldn't push the point though and rock the boat too hard. Maybe stay there a few days and get to know them and you may find you're welcome anytime.
You really don't want to upset the locals if you plan on doing a bit of fossicking in a certain area, if you get to know them info will come sooner or later. Like my Koori mate in Inverell refused to help me with gem spots when we first started chatting, after 5 trips up there and numerous beers each time in the pub he offered me a few spots to dig even after I said I didn't want his spots.
Just my 2c and my opinion.
You really don't want to upset the locals if you plan on doing a bit of fossicking in a certain area, if you get to know them info will come sooner or later. Like my Koori mate in Inverell refused to help me with gem spots when we first started chatting, after 5 trips up there and numerous beers each time in the pub he offered me a few spots to dig even after I said I didn't want his spots.
Just my 2c and my opinion.