The R.M. of Glen McPherson is located in the Great Plains of southwest Saskatchewan near the Canada-US border and directly north of the West Block of the Grasslands National Park. The RM encompasses 848.23 km2 (327.53 sq mi) of expansive rural tracts incorporating a mix of seeded crop land, native grasslands, and scenic southern prairie landscapes including the Wood Mountain uplands. The RM is bordered to the south and west by the RM of Val Marie No. 17, to the north by the RMs of Wise Creek No. 77, Auvergne No. 76, and Pinto Creek No. 75, and to the east by the RM of Mankota No. 45.

According to the 2021 Census, the RM population is 76 residents making it the least populated of Saskatchewan’s 296 Rural Municipalities. There are no villages or hamlets within its boundaries while all small historical settlements such as Billimun, Reliance, and Wallard, have dissolved. The closest serviced urban areas are the Village of Val Marie to the southwest and the Village of Mankota to the east. The closest large urban centre to the RM is the City of Swift Current, which is approximately 150 km northwest of the Village.

The RM was incorporated as a Rural Municipality on January 1, 1913. In 1931 the Canadian Pacific Railway conducted a survey of the southern portion of the RM with the intention of constructing a branch line between the Villages of Val Marie and Mankota. However, construction was abandoned due to prolonged drought and crop failure, giving the RM unique distinction of never containing a single town, village, or railway in Saskatchewan.