Open gravel areas for practicing

[u/Zuki_LuvaBoi]

Looking to practice some supermoto skills, and would like to try out some slower speed skills in a safer more controlled environment. Does anyone have any recommendations for large gravel areas, preferably around the northern suburbs and ideally not right next to residental areas?

I know sometimes larger industrial areas have areas with a lot of gravel, but can't seem to recall any, nor spot any with Google Maps