The cognitive dimensions of notations framework evaluation of the Gwich’in place names atlas interface utilized a modified version of Green & Blackwell’s (2000) cognitive dimensions evaluation to evaluate the Gwich’in Place Names atlas’ (http://atlas.gwichin.ca/index.html) interface usability. A use-case scenario was used to guide participants through the interface. Following the guided exploration researchers conducted a self -assessment survey and semi-structured interview. All guided explorations were video recorded and coded in order to analyze participants’ actions within the interface. These two approaches combined provide qualitative and quantitative evaluations of the Gwich’in place names atlas. The results of both evaluations outlined many usability issues related to the visibility, role expressiveness and viscosity of the interface. Usability tradeoffs were explored based on potential design maneuvers. We found that the cognitive dimensions of notations evaluation and lexicon are an appropriate low-cost, broad-brush evaluation method for online interactive cartographic interfaces.