Evening in Lone Tree cools off fast — the sun drops behind the Rampart Range, the air goes thin and sweet, and the lawns finally exhale after a long bright day. Oelmann Irrigation & Landscape Services LLC keeps those lawns mowed, trimmed and tended through the dry stretches when staying green takes real attention. The routes run from the newer streets along the RidgeGate corridor to the older blocks near the Arts Center, each yard cut to a consistent height so a whole row of them reads as one calm thing. There is a particular pleasure in the last pass of a mow, when the pattern closes up and the yard finally sits right. Beds edged, turf level, the property put back in order at the end of every visit.