Yet, Ket in central Asia and Navajo in south-central North America are very closely related. Sadly, Ket is close to dead, with only dozens of mostly elderly still fluent. Some suspect it was carried in a migration from Alaska back to Asia.
Languages used in British Columbia and Yukon are in the same family to those, but less similar. It is an example of a common phenomenon, where the extrema of a range retain older features. We see it also in far-west Celt and far-east Tocharian languages. It probably explains how rare genetic features are found in common in isolated South American, Australian, and Indian Ocean refugia, and nowhere between, and in pre-contact eastern US and western Europe haplogroups. Traces between get washed out by later influx.