The Semirechye is an isolated area, bordering China but separated from the bulk of (then) Russia by a vast dry steppe. It was very much a backwater of the civil war, with both Whites and Reds cut off from their political allies. The area was also known as Turkestan at the time.
Below are a couple of longish articles, covering Whites and Reds in the area:
Ivlev, M. Antibolshevik Forces in the Semirechensk Cossack Host. A brief historical sketch. White Guard #8. Posev 2005, pp. 225-235.
D. G. Simonov The Semirechensk Front in 1918: White Formations. The original is here.
The Red Army in Turkestan 1917-1920, Central Asian Review XIII
I have also organised some other information on the Semirechensk White forces: