The Taiga Plains play host to a variety unusual and sometimes rare geophysical features. This include such oddities as karsts, marl ponds, sink holes and alvars.

Karst is a limestone landscape, characterized by caves, fissures, and underground streams. It is unique in the Mackenzie and Slave Lowlands MB Ecoregions. The Nyarling River, located in the Slave Lowlands Mid-Boreal Ecoregion actually disappears in places and runs underground through bedrock caverns.

A thermokarst lake is a northern lake formed when water holds heat that thaws the permafrost below.

Alexandra and Louise Falls plunge from bedrock ledges along the Hay River. Elsewhere, bedrock exposures above the escarpment and near Kakisa Lake provide unique habitats, alvars, which support unusual plant communities. An alvar or pavement barren is a biological environment based on a limestone plain with thin or no soil and, as a result, sparse vegetation.