From my experience and reading other threads, you should post pictures of your problem so that the pros on here can better assess your problem.

My sense is that you should come to terms with the fact that you have a sloped yard and not a flat one. You could maybe do some diagonal terracing away from the house to make some level areas without changing the grade much right by the house.

Slopes actually make a yard far more interesting and have tons of landscape potential. People with flat properties have slope envy - ask me how I know! It's a bit like straight hair and curly hair though - no one's ever happy with what they have.

KarinL

Do you actually need the entire site graded to a plane for some kind of use? If not, why not grade what is gradable and expose the ledge for aesthetic reasons.

I'm not sure I can understand the exact layout of your yard without photos or a diagram, but it sounds like you have an answer here:

expose the ledge for aesthetic reasons -- laag's given you a great idea. Remove some of the dirt at the foot of the ledge, add a few dramatic shrubs or small trees (at the top, halfway down; wherever there's a good pocket of soil), fill in with rock-plants, and make the ledge a real showplace: the stunning backdrop for the rest of the yard ...

do some diagonal terracing away from the house to make some level areas without changing the grade much right by the house -- and add karinl's terraces: probably one or two terraces between the level around the house and the ledge. Exactly where the walls are placed will depend where you have bedrock and where you might have loose rock. Remember, you can always add soil (or some combination of stone/pavers and gravel) to an area to make it level. But work with the shape of the land itself: no right angles, no straight lines unless that's what the land wants to do. [At the property lines, you'll have to slope the terraces up or down a bit to meet the level of the neighbors' properties. Or just add some rocks.]

Each terrace will be just a step (maybe two) up from the previous level. No need for a railing at the walls: plant just above the walls, and that will keep people away from the edge. Maybe something that will trail down the wall and look interesting.

If your terrace walls are low, if they're built on bedrock, and if you use natural stone, it could even be a do-it-yourself project. Or you could hire someone to build the walls, and move the soil yourselves.

*sigh* Here I am, supposedly in the mountains, and everything's all covered with dirt. I'd be thrilled if my sloping lawn (with a much greater slope than the OP's) had some interesting bedrock under it that I could expose and garden around. Much more character than the sloping lawn I have!

Well, if I'm following this correctly, ignoring the rock ledge in the back, the slope is about 1 ft over 80 ft front to back, and about 2 ft over 40 ft side to side. There are an awful lot of places where that would *be* a flat lawn. It's certainly level enough for any yard uses I can think of.