When some people hear “mammoth,” money comes to mind. Local tour companies offer trips to the mammoth graveyards across the region’s Arctic frontier. Prospectors for mammoth parts—especially the tusks, known as ice ivory—have raced to collect remains. Around 100 tons of mammoth tusks are legally mined in Yakutia each year, while illegal mining is estimated at twice that much, according to a report by TASS “If ever a mammoth surfaces somewhere in the world, it will actually have Yakut roots,” said Mr. Fyodorov, proudly underscoring that his republic is mammoth central, the hereditary home of so many of these beasts....