My friend Kristina Gray has a series of posts on her blog about Karlag, the labor camp complex that operated in Karaganada Oblast, Kazakhstan from 1931 to 1959. She visited Dolinka, the administrative capitol of this section of the Gulag Archipelago. Karlag prisoners engaged in a wide variety of economic activities including agriculture, coal mining, limestone quarrying, glass manufacturing and food processing. At the end of 1943, a contingent of Russian-Germans mobilized into the labor army arrived at Karlag. By January 1944 they numbered 1,280 people including 488 women versus 50,080 convicted prisoners of which 20,572 were women. The labor army colonies in Karlag primarily worked in coal shaft no. 4. In January 1946, the NKVD demobilized the Russian-Germans working in the labor army at Karlag and reclassified them as special settlers. However, they still remained legally obligated to remain working in coal shaft no. 4 and other Karlag enterprises. The corrective labor camp complex in Karaganda Oblast continued to house prisoners for another thirteen years.
Source: A.A. German, "Sovetskie nemtsy v lageriakh NKVD v gody Velikoi Otechestvennoi Voiny: Vklad v pobedy," Voenno-istoricheskie issledovania v Povolzh'e , Sb. Nauch., (Saratov: Izd-vo: "Nauchnaia kniga," 2006), Issue no. 7, p. 297.