Some quick information about the topic at hand:

It is believed that they had reached Persia from Ancient Israel as early as the 8th century BC. They continued to migrate east, settling in mountainous areas of the Caucasus. The Mountain Jews survived numerous historical vicissitudes by settling in extremely remote and mountainous areas. They were known to be accomplished warriors and horseback riders.[10] The main Mountain Jew settlement in Azerbaijan is Qırmızı Qəsəbə, also called Jerusalem of the Caucasus.

Mountain Jews are distinct from Georgian Jews of the Caucasus Mountains. The two groups are culturally and ethnically different, speaking different languages and having many differences in customs and culture.

Mountain Jews have an oral tradition, passed down generation after generation, that they are descended from the Ten Lost Tribes which were exiled by the king of Assyria (Ashur), who ruled over northern Iraq from Mosul (across the Tigris River from the ancient city of Nineveh). The reference, most likely is to Shalmaneser, the King of Assyria who is mentioned in II Kings 18:9-12.

In the Second World War, some Mountain Jews settlements in Crimea and parts of their area in Kabardino-Balkaria were occupied by the German Wehrmacht at the end of 1942. During this period, they killed several hundreds of Mountain Jews until the Germans retreated early 1943. On September 20, 1942, Germans killed 420 Mountain Jews near the village of Bogdanovka. Some 1000–1500 Mountain Jews were murdered during the Holocaust.

Seems a bit, small, doesn't it?

Many Mountain Jews survived, however, because German troops did not reach all their areas; in addition, attempts succeeded to convince local German authorities that this group were "religious" but not "racial" Jews. With the help of their Kabardian neighbors, Mountain Jews of Nalchik convinced the local German authorities that they were Tats, the native people similar to other Caucasus Mountain peoples, not related to the ethnic Jews, who merely adopted Judaism.[26] The annihilation of the Mountain Jews was suspended, contingent on racial investigation.

Hmmm

The Soviet Army's advances in the area brought the Nalchik community under its protection.

Something about atheist soviet state protecting people seems... disingenuous to me.

In 1944, the NKVD deported the entire Chechen populace that surrounded the Mountain Jews in Chechnya, and moved other ethnic groups into their homes; Mountain Jews mostly refused to take the homes of deported Chechens[28] while there are some reports of deported Chechens entrusting their homes to Jews in order to keep them safe.

Hmmm, they got rid of everyone BUT them... and gave them everything that was there. Odd?

While elsewhere in the Russian Empire, Jews were prohibited from owning land (excluding the Jews of Siberia and Central Asia), at the end of the 19th and the beginning of the 20th century, the Mountain Jews owned land and were farmers and gardeners, growing mainly grain.

Stranger and stranger...

With increasing urbanization and sovietization in progress, by the 1930s, a layer of intelligentsia began to form. By the late 1960s, academic professionals, such as pharmacists, medical doctors, and engineers, were quite common among the community. Mountain Jews worked in more professional positions than did Georgian Jews, though less than the Soviet Ashkenazi community, who were based in larger cities of Russia. A sizable number of Mountain Jewish worked in the entertainment industry in Dagestan.

Spreading influence...

In the early decades of the Soviet Union, the government took steps to suppress religion. Thus, In the 1930s, the Soviet Union closed synagogues belonging to mountain Jews. Same procedures were implemented on other ethnicities and religions. Soviet authorities propagated the myth that Mountain Jews were not part of the world Jewish people at all, but rather members of Tat community that settled in the region

But that was because that was the lie they told the Nazi's to not get murdered... why play the victim about it. Oh... I forgot.

While Mountain Jews observed the rituals of circumcision, marriage and burial, as well as Jewish holidays,[43] other precepts of Jewish faith were observed less carefully.

I wonder what that means?