The Town of Johnstown is located in northeastern Rock County nine miles east of the City of Janesville. Johnstown Township is rural in nature with a significant percentage of its land being used for agricultural purposes. Johnstown Township can be divided into two distinctly different physical features: the southern third consisting of some of the most productive farmland in the Midwest and the northern two-thirds, termed the Johnstown moraine, consisting of rolling topography. Although not as intensely farmed as the southern one-third, because of the steeper slopes and woodlands, agriculture still plays a major role. The 2010 census of the Town of Johnstown was 778.