A switchback is a gift. It breaks the rhythm, gives you something to aim at, and lets you stand up out of the saddle for four seconds. Some long climbs never hand you one.
Mount Lemmon bends its way forty-six kilometres up the flank of the Catalinas and turns back on itself exactly once. Kitt Peak curves for nineteen kilometres to its observatory and never does at all. It is a different principle from an Alpine pass: instead of stacking corners up a headwall, an American mountain road traverses, working along the side of the range and taking the long way because there is room to.
You climb for two hours facing the same direction.