Siberian tigers were present in Alaska 100 000 years ago, and probably not only in this epoch of Prehistory. Tigers and lions cohabited on this territory.
At the end of upper Pleistocene, siberian populations, carriers of a very strong tiger culture (very influent in Northern China), migrate to America towards Beringia bridge.
The replaced the Tiger by the Jaguar in their cults.
Today, only for the USA, there are more than 10 000 captive tigers (two more times than in China).
This country (and more generally North America as a whole) has large wild areas where some tigers could live freely (circum – arctic zones included, in correspondance with present climatic changes) if prevalent bear areas are avoided.