This corner of the state is mostly sky — flat ground, a horizon that goes on for miles, and weather you can watch approaching for an hour before it ever gets to you. Northern Illinois Lawn Care works underneath all that, mowing, trimming and edging yards across Harlem on a weekly turn. Late summer is when the effort shows: the fields going gold while the lawns hold their green because somebody kept after them. Cleanups in spring and again in fall haul off whatever the open country blew in. The region is right there in the name, and the routes stay close to home — Harlem, Machesney Park, Roscoe and Rockford.