The first significant Canadian-born explorer, Louis Jolliet achieved international fame in his lifetime as the first non-Aboriginal person, together with Jacques Marquette, to travel and map the Mississippi River.
Even though this question is vague, the only answer that makes sense is Louis Joliet's mapping abilities. Louis went on numerous explorations, but his main interest was waterways. He detailed coastlines, rivers, lakes, and wrecks. His information was used by map makers to draw up maps of the region and released in Paris. He himself produced a map of the St. Lawrence River.
In 1694 he explored the coast of Labrador. It was one of the first successful trips made to and from Labrador. He kept journals, made sketches, and wrote descriptions of the people. He later taught Hydrography at the College of Quebec.
