Lewis and Clark did map the route to the pacific oceans though they were not able to find a direct water route as they had hoped. The Majority of their trip was along the Missouri River and thus it is the closest thing to a "Northwest Passage" that the explorers were able to find.
The reserves of oil and natural gas are formed and found in the sedimentary and igneous rocks mostly in the porous rocks as they have pores that allow for the water in small quantities to pass through them.
As the naturally occurring oil is drilled and mined from the ground in the oceans and lakes and mapping of their location is called as hydrocarbon kitchens
