Bogoras defines it outright, in a footnote at 1-035: “The high flat country between Penshina and Baron Korff’s Bays.” The isthmus joining Kamchatka to the mainland, bounded by Penzhina Bay on the Okhotsk side and Korf Bay on the Bering side.

The map's frame is measured from the two bays he names, not estimated. No source draws the Dol, so the frame says where to look, not where a boundary lies.