I need to add stairs to a dirt hill on the side of my house. The idea is to have stairs that lead down to the crawl space area of the home for easier maintenance. The grade is very steep, enough to say if you fall, you'll be like a pinball, bouncing off of trees. The top of the hill is just the top of the hill, all dirt, no ledger. I'm thinking about getting the precut stair stringers from home depot and using 4x4's set in concrete to support the stairs. Does anyone have any insight to what I should attach to at the top of the stairs if it's just a dirt hill? Should I cement in some posts and put a ledger between them?