The state border phenomenon in the Upper Ob-Irtysh area in the XVIII century is analyzed through the two key paradigms of perception (political and geographical images): cartographical and officially diplomatic. Essential differences among central, regional and local authorities, as well as diplomatic agents, land surveyors and travelers are considered as a consequence of the lack of state border’s delimitation and demarcation procedures between the Russian Empire and the Jungar Khanate. The authorities developed the idea of the “strategical border” and artificiality of state borders. The authors conclude that the territorial dispute created a unique situation of an “open” border, which was used by Russian authorities as a reason for further expansion I to Central Asia.