Guillaume de L’Isle

An interesting feature of this map is its reference to a western mountain range and a large body of salt water( “lac d’eau salée”) past the mountains (perhaps the Great Salt Lake of Utah or even the Pacific Ocean).  This is believed to be the first appearance of the Rocky Mountains on a printed map.  De L’Isle includes explanatory text on the map that these features were drawn from the writings of French explorer and adventurer Baron Louis de Lahontan, published in 1688.

The cartouche of the map appears to include a depiction of Niagara Falls.  The top of a wide waterfall appears above the map’s scale (which is given in French leagues, French nautical leagues, and common English leagues).  Beneath the scale is the bottom of the waterfall.  The effect created by the artist is of the water thundering down the cataract behind the diagram.  (Baron de Lahontan visited Niagara Falls and included a description in his writings.)  It was only five years before the printing of De L’Isle’s map that the first European illustration of the Falls was published, in the journal of Father Louis Hennepin