We are planning on a retaining wall this year but probably not until fall. I know the osb won’t last long but I have several scrap pieces so that’s what I used to combat the tires sinking into the ground. I have the other side up on 2x10 boards to level it side to side. I’m thinking about just buying a railroad tie and anchor it behind the back tire for now. I wanted the trailer where it is because when I connect to the truck the truck tires are still on asphalt driveway. I can just about guarantee if I backed down the hill further where my truck was in the grass I would get stuck, even in 4lo. I’ve gotten stuck on flat wet grass in the ram 3500 because of the crappy stock tires.