From the Wikipedia page 
The Zollernalbkreis is a Landkreis (district) in the middle of Baden-Württemberg, Germany. The district is located in the Swabian Alb, and contains the second highest elevation of this mountains, the 1011 meter high Oberhohenberg. In the south-east the district nearly reaches till the river Danube.
The district was created on January 1, 1973, when the two previous districts Balingen and Hechingen were merged.