Cherry Creek runs a green seam through this corner of Douglas County, cottonwoods leaning over the water and the trail already busy by seven in the morning. Lawns a few blocks off that corridor have to work harder for their color, with thin air, hard sun and a season that asks for attention rather than luck. Hassle-Free Lawns handles the weekly rounds: mowing at a height that shades its own roots, trimming close along fences and posts, edging the walks, and carrying off the clippings and the autumn litter. The name is the entire idea, which is that a homeowner comes back to a finished yard and nothing left to think about. At six thousand feet, cut grass smells sharper. It is a good thing to leave behind you.