“Sourdough was the prospector’s staff of life on the trail,” Superintendent MacKensie explained. “Once he got the mixture just right, he’d keep it in a tightly closed container and add to it as he used it. But the culture always remained the same.”

“Yeast is like a fungus,” Professor Crowell elaborated for the boys’ benefit. “It’s composed of living, growing cells.”

“Yes,” the superintendent went on. “This particular strain in the flapjacks we’re eating has been kept alive for sixty years by Frenchy’s family.”

Oui,” the cook spoke from the end of the table. “My papa give some of this sourdough to all his sons and daughters when they leave home. I give to my son some day.”

“Amazing,” said Lou Mayer.

Frenchy stood up and swung a big, empty platter up on one hand. “I go make some more, no?” He looked down at Jerry. “You eat five or six more, hey, boy? They very small.”

Jerry attacked the last flapjack on his plate with renewed relish. “A couple more anyway, Frenchy. And maybe another slab of that bacon.” He winked as Sandy began to groan. “Who knows, we may get stranded for days in a blizzard without food. I’m storing up energy.”

After breakfast, Sandy and Jerry went outside and watched Tagish Charley work out the huskies on the landing strip off to one side of the road station. The dog sled was about ten feet long with a welded aluminum frame and polished steel runners. Extending halfway down both sides, were guard rails to which baggage could be strapped. There was a small footrest at the rear, where the sled driver could ride standing erect, and a rubber-coated handrail for him to grip.

The dogs milled about excitedly as Charley harnessed them to the sled. They were hitched up in staggered formation, one dog’s head abreast of the haunches of the dog in front of him. Black Titan led the pack, and the driving reins were attached only to his harness.

“Lead dog, he have to be very smart,” Charley told them, ruffling up the thick fur collar around Titan’s throat. “He boss of team. Not driver. Other dogs do bad job, he scold them. Sometimes he have to fight a bad dog who make trouble.”