Along the southwest boundary of the RM is Katepwa Lake, which is one of the four Fishing Lakes in the Qu'Appelle Valley. The rest of the southern border follows the Qu'Appelle River.
In the 2021 Census of Population conducted by Statistics Canada, the RM of Abernethy No. 186 had a population of 337 living in 144 of its 165 total private dwellings, a change of -6.9% from its 2016 population of 362. With a land area of 763.11 km2 (294.64 sq mi), it had a population density of 0.4/km2 (1.1/sq mi) in 2021.[7]
In the 2016 Census of Population, the RM of Abernethy No. 186 recorded a population of 362 living in 150 of its 196 total private dwellings, a -6.5% change from its 2011 population of 387. With a land area of 779.42 km2 (300.94 sq mi), it had a population density of 0.5/km2 (1.2/sq mi) in 2016.[4]
The RM of Abernethy No. 186 is governed by an elected municipal council and an appointed administrator that meets on the second Tuesday of every month.[3] The reeve of the RM is John Fishley while its administrator is Karissa Lingelbach .[3] The RM's office is located in Abernethy.[3]