Missouri Secondary State Route Z is a short east-west highway in Southeastern Clark County. It runs from U.S. Rt. 61 west to Missouri State Route 81. MO Sec St Rt Z does not pass through any towns in Clark County. MO Sec St Rt Z is not multi-plexed in Clark County. MO Sec St Rt Z intersects the following highways in Clark County. U.S. Rt. 61, near Gregory Landing. Missouri Secondary State Route F, near Gregory Landing.