Has anyone had success with preparing a garden bed in the Rocky Mountains- zone 5 with the lasagna method?
YES ! Works great. I killed my front yard's grass last fall and planted a garden.
If you don't have enough newspapers, cardboard boxes (opened up to lay flat) work also.
Most soils in this area need a major infusion of organic matter so lasagne gardening is an ideal way to add a lot. Unless you are in a hurry it really is the easiest way to convert an area. I just finished converting the last of my yard which took me a year but at last all of the grass is gone. I certainly don't miss mowing, fertilizing and adding lots of expensive water to keep it green.