The first batch of 300,240 units of serum was delivered by train from Anchorage to Nenana, Alaska, where it was picked up by the first of twenty mushers and more than 100 dogs who relayed the serum a total of 674 miles (1,085 km) to Nome.
Before the night the temperature dropped to &minus;40 °F (&minus;40 °C), and the wind increased to 65 mi/h (105 km/h).