Keuka Park hangs on the west branch of Keuka Lake, where the ground falls toward the water in the same long tilt the grapevines use. JK Lawn Maintenance mows those slopes — college-side lawns, lake-road yards, the flat backs of houses that face all that blue. Cutting on a grade is a craft of its own: even stripes, no scalped rises, a finish that follows the land instead of fighting it. By afternoon in late summer the breeze comes uphill off the lake and dries the cut grass nearly as fast as it falls. Keuka Park, Branchport and Penn Yan get lawns kept trim on the slopes above the water.