Before the appearance of drones, how did power lines cross mountains and rivers?

At present, the UAV pay-off technology has been relatively mature and widely used. However, the wire laid by the UAV is not the wire that is ultimately used to transmit electric energy, but a light and high-strength guide rope, usually nylon rope. That is, the unmanned aerial vehicle (UAV) throws the nylon rope with a diameter of 3.5mm to the towers at all levels of the pay-off section, and then uses this traction rope to pull the Dinima guide rope with a diameter of φ 10mm to replace the original nylon rope with a diameter of 3.5 mm. After the entire Dinima guide rope runs through, the anti-torsion steel rope with a diameter of 15 is pulled to replace the Dinima guide rope with a diameter of 3.5 mm. Before the drone, I heard from the master that there were archery, air guns, hot air balloons and small manned aircraft.