Above Barton Pond the bluffs hold the last light a little longer than the rest of town, and on a winter evening you can watch snow start over the water before it ever reaches the road. Arbor Outdoor plows the long, curving drives up in that country and salts the turns that never see much sun. Summer changes the assignment but not the attention: mowing, edging, trimming, cleanups that leave beds sharp against the grass line. Working properties like these means knowing where a drift will build and where a hose won't reach — two different maps of the same ground. Ann Arbor asks for both kinds of knowledge, about six months apart.