Passage: During the later Pleistocene epoch, between 240,000 and 220,000 years ago, steppe wisent (B. priscus) migrated from Siberia into Alaska across the Bering Land Bridge. Bison priscus inhabited northern North America throughout the remainder of the Pleistocene. In western North America, B. priscus evolved into long-horned bison, B. latifrons, which then evolved into B. antiquus. The larger B. latifrons appears to have died out by about 20,000 ya. After the extinction of B. latifrons, B. antiquus became increasingly abundant in parts of midcontinent North America from 18,000 ya until about 10,000 ya, after which the species appears to have given rise to the living species, B. bison. B. antiquus is the most commonly recovered large mammalian herbivore from the La Brea tar pits.B. antiquus was taller, had larger bones and horns, and was 15-25% larger overall than modern bison. It reached up to 2.27 m (7.5 ft) tall, 4.6 m (15 ft) long, and a weight of 1,588 kg (3500 lb). From tip to tip, the horns of B. antiquus measured about 3 ft (nearly 1 m).

Question: When did steppe wisent migrate from Siberia to Alaska according to the geologic time scale?
between 240,000 and 220,000 years ago