Kars Oblast
Starting in 1841, the Doukhobors, and others, were resettled from southern Ukraine to Transcaucasia, where they founded a number of villages surrounded by mostly non-Russian speaking neighbors (primarily Azerbaijanis in Elisabethpol Governorate, Armenians in Tiflis Governorate, and likely a mix of both in the later (post-1878) settlements in Kars Oblast). These conditions allowed the dialect to develop in comparative isolation from the "mainstream" Russian.