Summer Storm - S1.E18

Ranger Headquarters is cut off by a violent storm as Matt Hammond lies poisoned by a snakebite. The phone line is down, the radio is not working, the serum is lost in the creek, the helicopter is out of fuel, the bridge is out and the ford is flooded. Skippy crosses an impassable gorge to fetch help, and the life-saving serum is parachuted to Ranger Headquarters just in time.