 The phrases "to the middle of the coast range of mountains" and "to the summit of the coast-range of mountains" were assumed to mean the dividing crest of the Olympic Mountains separating the Pacific, Juan de Fuca, and Hood Canal drainage basins.The phrase "thence southerly with said range of mountains to their intersection with the dividing ridge between the Chehalis and Quiniatl [sic] Rivers; thence westerly with said ridge to the Pacific coast" required further assumptions.The Fish and Wildlife project assumed the "southerly" line was to follow the main drainage divide between the Pacific and Hood Canal.