1925 serum run to Nome participant Gunnar Kaasen
Arrival in Minto
Half-Athabaskan Edgar Kalland arrived in Minto the night before, and was sent back to Tolovana, traveling 70 mi (110 km) the day before the relay. Shannon and his team arrived in bad condition at 11 am, and handed over the serum. After warming the serum in the roadhouse, Kalland headed into the forest. The temperature had fallen to −56 °F (−49 °C), causing Kalland's hands to freeze to the sled's handlebar, requiring the owner of the Manley Hot Springs roadhouse to pour boiling water on the birch wood bar for thawing.No new cases of diphtheria were diagnosed on January 28, but two new cases were diagnosed on January 29. The quarantine had been obeyed, but lack of diagnostic tools and the contagiousness of the strain rendered it ineffective. More units of serum were discovered around Juneau the same day. While no count exists, the estimate based on weight is roughly 125,000 units, enough to treat 4 to 6 patients. The crisis had become headline news in newspapers, including in San Francisco, Cleveland, Washington D.C., and New York, and spread to the radio sets which were just becoming common. The storm system from Alaska hit the contiguous United States, bringing record lows to New York, and freezing the Hudson River.
A fifth death occurred on January 30. Maynard and Alaskan House Delegate Daniel Sutherland renewed their campaign for flying the remaining serum by plane. Different proposals included flying a large aircraft 2,000 miles (3,200 km) from Seattle to Nome, carrying a plane to the edge of the pack ice via Navy ship and launching it, and the original plan of flying the serum from Fairbanks. Despite receiving headline coverage across the country and support from Arctic explorer Roald Amundsen, the plans were rejected by experienced pilots, the Navy, and Governor Bone. As publisher and editor of the Fairbanks Daily News-Miner newspaper, William Fentress Thompson harshly criticized government officials for inaction and funded a private fleet of planes.In response, Governor Bone decided to speed up the relay, authorizing additional drivers for Seppala's leg of the relay, so they could travel without rest. Seppala was still scheduled to cover the most dangerous leg, the shortcut across Norton Sound, but the telephone and telegraph systems bypassed the small villages he was passing through, and there was no way to tell him to wait at Shaktoolik. The plan relied on the driver from the north catching Seppala on the trail. Summers arranged for drivers along the last leg, including Seppala's colleague Gunnar Kaasen.
From Manley Hot Springs, the serum passed through largely Athabascan hands before George Nollner delivered it to Charlie Evans at Bishop Mountain on January 30 at 3 am. The temperature had warmed slightly, but at −62 °F (−52 °C), was dropping again. Evans relied on his lead dogs when he passed through ice fog where the Koyukuk River, flowing into the Yukon, had broken through and surged over the ice, but forgot to protect the groins of his two short-haired mixed breed lead dogs with rabbit skins. Both dogs collapsed with frostbite, with Evans having to take their place himself pulling the sled. He arrived at 10 am; both dogs were dead. Tommy Patsy departed within half an hour.
The transport of the serum then parted ways with the Yukon River as the river turned south and the trail crossed the Kaltag Portage west to the coast. Athabascan Jack Nicolai, aka "Jackscrew", took it up the first half of the portage to Old Woman Cabin and Victor Anagick of the Inupiat village Unalakleet, having driven up to meet him there, took it down the second half, handing it to his fellow villager Myles Gonangnan on the shores of Norton Sound in Unalakleet on January 31 at 5 am. Gonangnan saw the signs of a storm brewing, and decided not to take the shortcut across the dangerous ice of the Sound. He departed at 5:30 am, and as he crossed the hills, "the eddies of drifting, swirling snow passing between the dog's legs and under the bellies made them appear to be fording a fast running river.": 203  The whiteout conditions cleared as he reached the shore, and the gale-force winds drove the wind chill to −70 °F (−57 °C). At 3 pm, he arrived at Shaktoolik. Seppala was not there, but Henry Ivanoff was waiting just in case.
On January 30, the number of cases in Nome had reached 27 and the antitoxin was depleted. According to a reporter living in Nome, "All hope is in the dogs and their heroic drivers ... Nome appears to be a deserted city.": 205  With the report of Gonangnan's progress on January 31, Welch believed the serum would arrive there in February.